Breeding method of puffed corn for Korean popcorn

Abstract

The invention belongs to the technical field of corn breeding, and particularly relates to a breeding method of puffed corn for Korean corn popcorn, which comprises the following steps: selecting a parent of a burst type corn single cross breed and a parent of a hard grain type corn or semi-purslane type corn single cross breed, and hybridizing in a female parent-female parent form and a male parent-male parent form; performing backcross by taking the parent of the burst type corn as a male parent, and performing diploid induction to obtain a female parent line induced single grain and a male parent line induced single grain, thereby correspondingly inducing a single plant and performing selfing to obtain a single ear; the method comprises the following steps: sowing seeds into ear rows, carrying out field phenotype identification and screening, selfing, harvesting and testing seeds, carrying out popcorn detection and screening on selected ear row seeds, finally screening out a female parent line selfing line and a male parent line selfing line, and hybridizing to obtain hybrids; hybrid seeds are sown, one hybrid seed is selected, and the puffed corn more suitable for the Korean corn flowers is cultivated.

Description

Technical Field

[0001] This invention belongs to the field of maize breeding technology, and in particular relates to a breeding method for puffed maize used in Korean-style popcorn. Background Technology

[0002] Traditional popcorn uses regular corn, the kind typically used for animal feed, and is popped into popcorn under high temperature and pressure in a special pot. It contains no oil, sugar, or additives; the method is simple, and the flavor is natural; this is now called old-fashioned popcorn. Later, a commercially available type of corn specifically for popping corn appeared: popcorn corn. This type of corn doesn't require special equipment; it pops easily by roasting it in a pot under normal pressure. Popcorn corn (…) Zea mays L var. ewerta Sturt Popcorn is one of the earliest types of corn, botanically belonging to a subspecies of Zea in the genus Zea of ​​the family Poaceae, also known as a variety. Popcorn is further divided into three categories based on flower shape: spherical popcorn, butterfly popcorn, and mixed-flower popcorn, used to process different types of popcorn products. For example, spherical popcorn is used to make caramel popcorn, butterfly popcorn is mainly used for microwave popcorn, and mixed-flower popcorn is more suitable for cinemas and street vendors for freshly made popcorn. Whether spherical or butterfly-shaped, popcorn does not require high-pressure sealing equipment, making it easy to add various ingredients such as cream, sugar, chocolate, milk powder, and flavorings. Popcorn made from popcorn originated in the United States and is therefore also called American popcorn. It can come in various patterns, with diverse flavors, good taste, and rich nutrition. Popcorn can also be freshly stir-fried in a wok at home for a rich aroma.

[0003] While American-style popcorn made with popcorn kernels is delicious, people still crave the taste of traditional popcorn. Thus, another type of popcorn was created. This type uses purebred popcorn kernels as its raw material and is popped using an old-fashioned high-temperature, high-pressure popcorn machine (commonly known as an "iron gourd" or "cannon machine"). Because it was first introduced in South Korea, it is called Korean-style popcorn. Korean-style popcorn uses the old-fashioned popping method, so it generally leans more towards the flavor of traditional popcorn while also incorporating the advantages of American-style popcorn. It retains the burnt aroma and crispy texture of traditional popcorn, while being more visually appealing than American-style popcorn and more suitable for coating, especially for making milder popcorn varieties. Although old-fashioned, American-style, and Korean-style popcorn each have their own advantages, they also each have some drawbacks and shortcomings. The defects of old-fashioned popcorn: First, the popcorn made from feed corn is hard and not crispy enough, making it unsuitable for children; second, the shape of the popcorn is not good, being flat and not round; third, the surface of the popcorn is rough with small burrs; fourth, the corn husks are not completely removed; and fifth, the germ accounts for a large proportion, and the germ part becomes dark brown, burnt, and has a poor taste after puffing.

[0004] The drawbacks of American popcorn: Popcorn comes in two main varieties: spherical and butterfly-shaped. Butterfly-shaped popcorn and microwave popcorn made from butterfly varieties are prone to breakage, resulting in fewer product variations and a less appealing appearance. Caramel popcorn made from spherical varieties, while round, is not perfect: First, the spherical formation rate is not 100%, still containing a certain number of irregularly shaped, nearly butterfly-shaped popcorn pieces. Second, the surface of the popcorn is prone to developing small burrs from the bursting, leading to a higher consumption and loss of oil, sugar, and other ingredients during the sugar coating process, thus reducing the yield. Third, the popcorn texture is too loose, resulting in a hollow and less crisp texture, thus requiring a caramel coating to enhance its crispness. Fourth, it lacks the rich aroma of traditional popcorn. Fifth, some husks are not completely removed, making it unsuitable for children. Sixth, the corn yield is lower, resulting in higher planting costs.

[0005] The drawbacks of Korean-style popcorn: Its advantage lies in maintaining the flavor and texture of traditional popcorn, thanks to the use of an old-fashioned popcorn machine. However, because it uses the same purebred popcorn as American popcorn, the popcorn is too loose, hollow, lacks chewiness, has poor crispness, a weak burnt aroma, and the kernels are not large enough. Additionally, the corn yield is relatively low. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a breeding method for puffed corn used in Korean popcorn processing. Based on the specific requirements of Korean popcorn processing for raw corn, different subspecies of corn, namely the popping subspecies (…), are used… Zea mays L var. ewerta Sturt ), hard-grained subspecies ( Zea mays L subsp. indentata ) and the semi-dentate subspecies ( Zea mays L semindentata Kulesh The beneficial genes of popcorn are introduced into popcorn, and then diploid induction technology (genotype fixation) is used to quickly breed popcorn that is more suitable for Korean popcorn.

[0007] The corn used in current Korean-style popcorn processing is the same type of corn used in American popcorn, namely popcorn, a purebred popcorn variety. The most critical technical indicators in popcorn breeding are the popping ratio, popcorn shape, and kernel weight (kernel size), with the popping rate being the last. Among these indicators, the popping ratio is the most challenging, requiring a ratio of 35 to 40 times (popcorn volume / kernel volume) for butterfly-shaped popcorn and 25 to 28 times for spherical popcorn. To achieve such high ratios, the popping ratio of the breeding stock is extremely important. Experts in this field know that popcorn breeding must use popcorn as the raw material; the most undesirable practice is to mix non-popcorn components into the raw material, otherwise it will be difficult to develop valuable varieties. Especially for butterfly-shaped popcorn varieties, the infiltration of other lineages will significantly reduce the popping ratio, even to less than 20 times, resulting in a substantial decrease in popcorn shape and taste. This is because American popcorn relies on the inherent genetic characteristic of popping within the corn itself, rather than the external force of the popping machine.

[0008] Korean popcorn is made using the external force of an extruder. It utilizes the principle of instantaneous decompression under high temperature and pressure, so any type of corn can be popped (old-fashioned popcorn), even soybeans, peanuts, and wheat. Although the popping principle of Korean popcorn differs from that of American popcorn, there are currently no corn varieties specifically designed for Korean popcorn, and Korean popcorn requires spherical popcorn. Therefore, for now, we can only borrow the spherical popcorn varieties used in American popcorn.

[0009] Based on the characteristics that Korean popcorn has lower requirements for the popping ratio and flower shape (American popcorn testing standards) of raw corn than American popcorn varieties, but higher requirements for kernel size and popcorn taste, this invention establishes corresponding technical indicators for the breeding of Korean popcorn varieties: 1. Spherical flowers, ensuring the rounded flower shape of existing Korean popcorn; 2. Large kernels, with kernel weight and popcorn size more than 20% higher than pure popcorn varieties; 3. Good taste, with a taste superior to existing Korean popcorn, closer to traditional popcorn, with a firm texture and chewiness; 4. High yield, with a yield increase of more than 20% compared to existing pure popcorn varieties.

[0010] Based on this breeding objective, this invention utilizes the established breeding technology route to introduce beneficial genes from the flint and semi-dent subspecies into purebred popcorn. First, leveraging the genetic characteristics of the flint and semi-dent subspecies—larger kernels and lower endosperm corn keratinization compared to popcorn subspecies—the compactness of the popcorn is increased by reducing endosperm fullness, thus increasing kernel and popcorn volume. Second, by controlling endosperm corn keratinization and selecting kernel shape, the popcorn's pelleting rate, sphericity, and compactness are ensured. Third, using an old-fashioned popcorn machine for popping, and through popcorn testing, tasting, and screening, a popcorn variety with larger size, crisper texture, chewier texture, and purer flavor is bred, better meeting the processing requirements of Korean-style popcorn. Specifically, this invention provides a breeding method for puffed corn used in Korean-style popcorn production, including the following steps: Step 1: Select superior parents of popcorn single cross (A×B) and parents of flint or semi-dent maize single cross (C×D), and perform crosses in the form of female parent to female parent (introducing 50% of flint or semi-dent maize genes into popcorn female parent line A) and male parent to male parent (introducing 50% of flint or semi-dent maize genes into popcorn male parent line) to obtain F1-1 and F1-2; Step 2: Using F1-1 and F1-2 as female parents, backcross with popcorn as male parents to obtain F2-1 and F2-2, thus obtaining two test materials containing 25% of the genes of flint maize or semi-dent maize. Step 3: Diploid induction was performed on F2-1 and F2-2 to obtain homozygous maternal and paternal induced single grains; Step 4: Sow the female parent line and the male parent line to induce single seeds, obtain induced single plants of the female parent line and the male parent line, and self-pollinate them to obtain single ears of homozygous genotypes of the female parent line and the male parent line. Step 5: Sow the single ears of homozygous maternal and paternal lines into ear rows for field phenotypic identification and screening. Selected ear rows are self-pollinated and tested after harvest. The kernels of the selected ear rows are tested for popping and screening. Finally, a number of maternal and paternal inbred lines of equal number are selected. Step 6: Cross the maternal inbred line and the paternal inbred line to obtain several hybrids; Step 7: Sow several hybrid varieties. Based on the standards in Step 5, conduct field phenotypic identification, indoor seed testing, and popping test on the five hybrid varieties. Based on the comprehensive identification results, select one hybrid variety to cultivate a popped corn variety for Korean-style corn popping.

[0011] Preferably, in step 1, the parents selected are the popcorn single cross 'Jiaqiu 105' and the semi-dent corn single cross 'Tieyan 388'.

[0012] Preferably, in step 1, the parents selected are the popcorn single-cross hybrid 'Jiaqiu 105' and the flint corn single-cross hybrid 'Demeya 1'.

[0013] Preferably, in step 1, the parents selected are the popcorn single cross 'Jiaqiu 140' and the semi-dent corn single cross 'Shendan 10'.

[0014] Preferably, in step 5, when conducting field phenotypic identification and screening, plants with plant shape, leaf color, and tassel branching that are intermediate between the parents are selected.

[0015] Preferably, in step 5, the following criteria are used for seed selection: long cylindrical ear shape, 14-16 rows per ear, 100-kernel weight of 24-28 grams, embryo size accounting for 2-4% of the total kernel size, corneous endosperm accounting for 92-96% of the total endosperm, growth period of 120-130 days, compact or semi-compact plant shape, zero natural field incidence of stalk rot, head smut, head smut, and ear grain rot, and lodging rate of less than 5%; the selection criteria for popcorn are large popcorn, round popcorn shape, light corn color, and crispy taste.

[0016] Preferably, in step 5, the popcorn screening uses a sealed high-pressure popcorn machine.

[0017] The puffed corn bred using the above-mentioned breeding methods significantly improves the eating and processing quality of Korean popcorn, enhances heterosis, and strengthens corn yield, disease resistance, stress resistance, and adaptability. By introducing beneficial genes from different subspecies of corn, kernel weight and kernel volume are increased, resulting in larger popcorn kernels; the popcorn's firmness and crispness are improved, and its taste is better than Korean and American popcorn processed from purebred popcorn, as well as old-fashioned popcorn made from ordinary corn; the popcorn's head formation rate and roundness are significantly improved; supplemented by diploid induction technology and conventional techniques, the breeding speed of puffed corn is greatly accelerated, and the breeding efficiency is significantly improved.

[0018] Compared with the prior art, the advantages of the present invention are as follows: 1. Increased the volume of popcorn; By increasing the volume and weight of the corn kernels, the volume of the popcorn is significantly increased, with the kernel volume increasing by about 20% compared to pure popcorn and more than 20% higher than the individual popcorn volume of existing Korean popcorn varieties. 2. Improved taste; Korean popcorn made from this puffed corn is fluffier and crispier than popcorn made from regular old-variety corn. It is also significantly firmer and crispier than Korean popcorn made from pure popcorn. It has a chewy texture and a burnt flavor that is closer to old-fashioned popcorn. 3. More conducive to food processing; Popcorn made with this type of puffed corn is typically spherical, with perfectly round kernels. This overcomes the shortcomings of traditional popcorn, such as a rough surface, a square shape rather than a round shape, incomplete hull removal, a large proportion of germ, and a burnt color. While increasing the volume of the popcorn, it retains the round, spherical appearance of purebred popcorn. The surface of the popcorn is smooth and even, which is beneficial for coating with flour and sugar. This saves on ingredients and avoids the high sugar and oil content of the popcorn, making it particularly suitable for processing milder popcorn. 4. High corn yield and low raw material cost; After introducing genetic material from different subspecies, combining ability is improved, ears become larger, 100-kernel weight increases, and ultimately yield per unit area is significantly increased, while the cost of raw corn is reduced. At the same time, it exhibits strong growth vigor, disease resistance, lodging resistance, salt tolerance, and other stress resistance, making it more adaptable and resulting in higher and more stable yields. Attached Figure Description

[0019] Figure 1 Comparative images of the appearance of existing Korean popcorn kernels (left), Korean popcorn kernels of Embodiment 1 of the present invention (middle), and hard-kernel subspecies corn kernels (right); Figure 2 Comparison of the appearance of existing Korean-style popcorn (left) and popcorn of Embodiment 3 of the present invention (right). Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0021] The principle of this invention is to utilize the characteristics of flint and semi-dent subspecies of corn, which have lower endosperm fullness, larger endosperm porosity, and larger kernel volume compared to popcorn subspecies. The beneficial genes of flint or semi-dent subspecies are introduced into popcorn subspecies. By appropriately increasing the starchy component of the endosperm, reducing endosperm fullness, and increasing porosity, the explosive force is appropriately reduced, thereby improving the firmness of the popcorn. This overcomes the defects of existing Korean popcorn, which uses purebred American popcorn and is overly fluffy and lacks a substantial texture. The resulting popcorn is firmer, chewier, and crispier. The increased endosperm porosity prolongs the time required to reach the required steam pressure for popping, resulting in a stronger burnt aroma and a flavor closer to traditional popcorn.

[0022] By leveraging the superior hybrid vigor, higher yield, and greater resistance and adaptability of the flint and semi-dent subspecies compared to the bursting subspecies, beneficial genes are introduced to create a maize variety that falls between the two subspecies, resulting in a significant improvement in yield, disease resistance, stress tolerance, and adaptability.

[0023] The "diploid induction technology" is used to fix the heterozygous genotype after introduction, quickly obtain inbred lines, and shorten the breeding cycle.

[0024] Example 1: Cultivation of mid-to-late maturing Korean-style popcorn; Take the following steps: 1. Select the male and female parents (TQ-5 × TQ-10) of the popcorn single-cross maize variety 'Jiaqiu 105' (nationally approved maize variety, approval number: Guoshen maize 20180182), and the male and female parents (Tie T0908 × Tie T080) of the mid-late maturing semi-dent maize single-cross maize variety 'Tieyan 388' (Liaoning Province approved maize variety, approval number: Liaoshen maize 2017054); use 'TQ-5', the female parent of 'Jiaqiu 105', as the female parent, and 'Tieyan 388' as the female parent. The maternal parent 'Tie T0908' (a semi-dent subspecies) was used as the paternal parent in a cross, and the genetic material of 'Tie T0908' was introduced into the popping maize maternal line to obtain (TQ-5 × Tie T0908); the paternal parent 'TQ-10' of 'Jiaqiu 105' was used as the maternal parent, and the paternal parent 'Tie T080' (a semi-dent subspecies) of 'Tieyan 388' was used as the paternal parent in a cross, and the genetic material of 'Tie T080' was introduced into the popping maize paternal line to obtain (TQ-10 × Tie T080); 2. Sow seeds of the previous generation (TQ-5 × Iron T0908), use (TQ-5 × Iron T0908) as the female parent and TQ-5 as the male parent to perform backcrossing, obtaining (TQ-5 × Iron T0908) × TQ-5 containing 25% semi-dent maize genetic material; sow seeds of the previous generation (TQ-10 × Iron T080), use (TQ-10 × Iron T080) as the female parent and TQ-10 as the male parent to perform backcrossing, obtaining (TQ-10 × Iron T080) × TQ-10 containing 25% semi-dent maize genetic material; 3. Sow 100 plants of (TQ-5×IronT0908)×TQ-5 obtained from the previous generation, and induce them using diploid induction technology to obtain 60 induced single seeds of the maternal line; sow 100 plants of (TQ-10×IronT080)×TQ1-0 obtained from the previous generation, and induce them using diploid induction technology to obtain 60 induced single seeds of the paternal line. 4. Sow the previous generation maternal line to induce single grains, obtain 55 first generation maternal line induced single plants, self-pollinate, and select 50 ears after harvest for seed selection; sow the previous generation paternal line to induce single grains, obtain 55 first generation paternal line induced single plants, self-pollinate, and select 50 ears after harvest for seed selection. 5. Sow single ears of maternal lines obtained from the previous generation, sowing 50 rows of ears. After field phenotypic identification and screening, select 20 homozygous rows that meet the breeding objectives in terms of medium-late maturity, disease resistance, stress resistance, lodging resistance, and plant type. Self-pollinate these rows, and test them after harvest. During the testing, select rows that meet the breeding objectives with high corneum degree, small embryo, and round grain shape. Use a high-pressure popcorn machine to pop the selected rows for flower testing and screening. Select rows with large, round, light-colored, and crispy flowers. Based on the combined results of field phenotypic, indoor testing, and quality evaluation, select 5 rows, which are the 5 maternal inbred lines. The paternal line obtained from the previous generation was sown, and 50 ear rows were sown. After field phenotypic identification and screening, 20 homozygous ear rows that met the breeding objectives in terms of medium-late maturity, disease resistance, stress resistance, lodging resistance, and plant type were selected. These were self-pollinated and tested after harvest. During the testing, ear rows that met the breeding objectives were selected with high cornein content, small embryo size, and round kernel shape. The selected ear rows were popped with a high-pressure popcorn machine for corn popping test and screening. Ear rows with large, round, light-colored, and crispy kernels were selected. Based on the combined results of field phenotypic, indoor testing, and quality evaluation, 5 ear rows were selected, which are the 5 paternal line inbred lines. 6. Sow the inbred lines of the previous generation, using 5 female inbred lines as female parents and 5 male inbred lines as male parents, and crossbreed to form 5 hybrid varieties; 7. Five hybrid seeds obtained from the previous generation were sown, and field phenotypic identification and indoor seed testing were carried out according to the above breeding objectives. The five hybrids were popped using a high-pressure popcorn machine to test their popping ability. Based on the combined results of field phenotypic, indoor seed testing and quality identification, one hybrid was finally selected. Thus, a mid-to-late maturing Korean popcorn puffed corn variety specifically for processing Korean popcorn was successfully bred, tentatively named 'Popcorn No. 1'. When 'Banghua No. 1' is planted for raw corn production, the yield is over 600 kg per mu, which is about 30% higher than the original purebred popcorn 'Jiaqiu 105'. The weight of 100 kernels increases, and the resistance, adaptability and salt tolerance are significantly enhanced. The corn kernels are 25% larger than 'Jiaqiu 105', with a 100% spherical rate, and are typical round in shape, without burrs or cracks. The taste is crisper and the aroma is richer than that of purebred popcorn.

[0025] Example 2: Cultivation of early-maturing Korean-style popcorn; Take the following steps: 1. Select the male and female parents of the superior popping maize single cross 'Jiaqiu 105' (TQ5×TQ10), and then select the male and female parents of the early-maturing flint maize single cross 'Demeya No. 1' (Heilongjiang Province approved maize variety, approval number: Heishenyu 2004014) (KWS10.KWS73×KWS49); use 'T-Q5', the female parent of 'Jiaqiu 105', as the female parent, and 'KWS10.KWS73', the female parent of 'Demeya No. 2'. A hybrid was formed using '(flint type subspecies)' as the male parent, and 50% of the genetic material of flint maize was introduced into the popcorn maize female parent line to obtain (TQ-5×KWS10.KWS73); a hybrid was formed using 'TQ-10' (the male parent of 'Jiaqiu 105') as the female parent and 'KWS49' (the male parent of 'Demeya 2') (flint type subspecies) as the male parent, and 50% of the semi-dent maize genes were introduced into the popcorn maize male parent line to obtain (TQ-10×KWS49). 2. Sow seeds of the previous generation (TQ-5×KWS10.KWS73), use (TQ-5×KWS10.KWS73) as the female parent and 'TQ-5' as the male parent to perform backcrossing, obtaining (TQ-5×KWS10.KWS73)×TQ-5 containing 25% of the flint maize gene; sow seeds of the previous generation (TQ-10×KWS49), use (TQ-10×KWS49) as the female parent and 'TQ-10' as the male parent to perform backcrossing, obtaining (TQ-10×KWS49)×TQ-10 containing 25% of the semi-dent maize gene; 3. Sow 100 plants of (TQ-5×KWS10.KWS73)×T-Q5 obtained from the previous generation, and induce them using diploid induction technology to obtain 60 induced single seeds of the maternal line; sow 100 plants of (TQ-10×KWS49)×TQ-10 obtained from the previous generation, and induce them using diploid induction technology to obtain 60 induced single seeds of the paternal line. 4. Sow the induced single seed of the previous generation maternal line to obtain 55 induced first generation single plants of the maternal line, self-pollinate, and select 50 ears after harvest for seed selection; sow the induced single seed of the previous generation paternal line to obtain 55 induced first generation single plants of the paternal line, self-pollinate, and select 50 ears after harvest for seed selection. 5. Sow single ears of maternal lines obtained from the previous generation, sowing 50 rows of ears. After field phenotypic identification and screening, select 20 homozygous rows that meet the breeding objectives in terms of early maturity, disease resistance, stress resistance, lodging resistance, and plant type. Self-pollinate these rows and test them after harvest. During the testing, select rows with high corneum content, smaller embryos, and rounder grains that meet the breeding objectives. Use a high-pressure popcorn machine to pop the selected rows and test for flowers. Select rows with large, round, light-colored flowers and crisp taste. Based on the combined results of field phenotypic, indoor testing, and quality evaluation, select 5 rows of ears, i.e., 5 maternal inbred lines. Single ears of the paternal line obtained from the previous generation were sown, and 50 ear rows were sown. After field phenotypic identification and screening, 20 homozygous ear rows that met the breeding objectives in terms of early maturity, disease resistance, stress resistance, lodging resistance, and plant type were selected. These rows were self-pollinated and tested after harvest. During the testing, ear rows that met the breeding objectives were selected with high corneum, small embryos, and round grains. The selected ear rows were popped with a high-pressure popcorn machine for flower testing and screening. Ear rows with large, round, light-colored, and crispy flowers were selected. Based on the combined results of field phenotypic, indoor testing, and quality evaluation, 5 ear rows were selected, which are 5 paternal line inbred lines. 6. Sow the inbred lines of the previous generation, using the inbred lines of 5 maternal lines as female parents and the inbred lines of 5 paternal lines as male parents, and crossbreed to form 5 hybrid varieties; 7. Sow the five hybrid seeds obtained from the previous generation, and conduct field phenotypic identification, screening, and indoor seed testing according to the above breeding objectives; use a high-pressure popcorn machine to pop the five hybrids and conduct popping tests on the field phenotypic, indoor seed testing, and quality identification results, and select one hybrid seed from them. Thus, an early-maturing Korean-style popcorn popcorn was successfully bred, tentatively named 'Popcorn No. 2'.

[0026] When 'Banghua No. 2' is planted for raw corn production, the yield is over 600 kg per mu, which is about 25% higher than the original purebred popcorn 'Jiaqiu 105'. The weight of 100 kernels increases, and the stress resistance, adaptability and salt tolerance are significantly enhanced. The corn kernels are about 25% larger than 'Jiaqiu 105', with a 100% spherical rate, and are typical round in shape, without burrs or cracks. The taste is crisper and the aroma is richer than that of purebred popcorn.

[0027] Example 3: Cultivation of late-maturing Korean-style popcorn: Take the following steps: 1. Take the male and female parents (TQ-10 × M1Q193) of the popcorn single-cross maize 'Jiaqiu 140' (nationally approved maize variety, approval number: Guoshenyu 20231064), and the male and female parents (Shen 137 × Q1261) of the late-maturing semi-dent maize single-cross 'Shendan 10' (nationally approved maize variety, approval number: Guoshenyu 990003); use 'TQ-10', the female parent of 'Jiaqiu 140', as the female parent, and 'Shendan 10' as the female parent. Crossing was performed with the maternal parent 'Shen 137' (a semi-dent subspecies) as the paternal parent, introducing 50% of the semi-dent maize genetic material into the popcorn maize maternal line to obtain (TQ-10 × Shen 137); crossing was performed with the paternal parent 'M1Q193' of 'Jiaqiu 140' as the maternal parent and the paternal parent 'Q1261' (a flint subspecies) of 'Shendan 10' as the paternal parent, introducing 50% of the semi-dent maize genes into the popcorn maize paternal line to obtain (M1Q193 × Q1261). 2. Sow seeds of the previous generation (TQ-10 × Shen 137), use (TQ-10 × Shen 137) as the female parent and TQ-10 as the male parent to perform backcrossing, obtaining (TQ-10 × Shen 137) × TQ-10 containing 25% semi-dent maize genetic material; sow seeds of the previous generation (M1Q193 × Q1261), use (M1Q193 × Q1261) as the female parent and M1Q193 as the male parent to perform backcrossing, obtaining (M1Q193 × Q1261) × M1Q193 containing 25% semi-dent maize genetic material; 3. Sow 100 plants of (TQ-10×Shen137)×TQ-10 obtained from the previous generation, and induce them using diploid induction technology to obtain 60 induced single seeds of the maternal line; sow 100 plants of (M1Q193×Q1261)×M1Q193 obtained from the previous generation, and induce them using diploid induction technology to obtain 60 induced single seeds of the paternal line. 4. Sow the induced single seed of the previous generation maternal line to obtain 55 induced first generation single plants of the maternal line, self-pollinate, and select 50 ears after harvest for seed selection; sow the induced single seed of the previous generation paternal line to obtain 55 induced first generation single plants of the paternal line, self-pollinate, and select 50 ears after harvest for seed selection. 5. Sow single ears of maternal lines obtained from the previous generation, sowing 50 rows of ears. After field phenotypic identification and screening, select 20 homozygous rows that meet the breeding objectives in terms of late maturity, disease resistance, stress resistance, lodging resistance, and plant type. Self-pollinate these rows, and test them after harvest. During the testing, select rows that meet the breeding objectives with high corneum, small embryos, and round grains. Use a high-pressure popcorn machine to pop the selected rows for flower testing and screening, selecting rows with large, round, light-colored, and crispy flowers. Based on the combined results of field phenotypic, indoor testing, and quality measurement, select 4 rows of ears, i.e., 4 maternal inbred lines. Fifty single-ear rows of male parent lines obtained from the previous generation were sown. After field phenotypic identification and screening, 20 homozygous rows that met the breeding objectives in terms of late maturity, disease resistance, stress resistance, lodging resistance, and plant type were selected. These rows were self-pollinated and tested after harvest. During the testing, rows that met the breeding objectives were selected with high corneum, small embryos, and round grains. The selected rows were popped with a high-pressure popcorn machine for flower testing and screening. Rows with large, round, light-colored, and crispy flowers were selected. Based on the combined results of field phenotypic, indoor testing, and quality measurement, four rows were selected, which are the four male parent inbred lines. 6. Sow the inbred lines of the previous generation, using 4 female inbred lines as female parents and 4 male inbred lines as male parents, and crossbreed to form 4 hybrid varieties; 7. Sow the four hybrid seeds obtained from the previous generation, and conduct field phenotypic identification, screening, and indoor seed testing according to the above breeding objectives; pop the seeds with a high-pressure popcorn machine to test the popping of the four hybrid corn varieties; select one hybrid seed from the results of field phenotypic, indoor seed testing, and quality determination. Thus, a late-maturing Korean-style popcorn popcorn was successfully bred and is tentatively named 'Popcorn No. 3'.

[0028] When 'Banghua No. 3' is planted for raw corn production, the yield is over 600 kg per mu, which is about 30% higher than the original purebred popcorn 'Jiaqiu 140'. The weight of 100 kernels increases, and the stress resistance, adaptability and salt tolerance are significantly enhanced. The corn kernels are 25% larger than 'Jiaqiu 140', with a 100% spherical rate, and are typical round in shape, without burrs or cracks. The taste is crisper and the aroma is richer than that of purebred popcorn.

[0029] The above description is merely a preferred embodiment of the present invention and is illustrative rather than restrictive. Those skilled in the art will understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims, all of which will fall within the protection scope of the present invention.

Claims

1. A breeding method for puffed corn used in Korean-style popcorn, characterized in that, Includes the following steps: Step 1: Select the parents of popcorn single cross, flint corn or semi-dent corn single cross, and perform crosses in the form of female parent to female parent and male parent to male parent to obtain F1-1 and F1-2; Step 2: Using F1-1 and F1-2 as female parents, backcross with popcorn as male parents to obtain F2-1 and F2-2 respectively; Step 3: Diploid induction was performed on F2-1 and F2-2 to obtain homozygous maternal and paternal induced single grains; Step 4: Sow the female parent line and the male parent line to induce single seeds, obtain induced single plants of the female parent line and the male parent line, and self-pollinate them to obtain single ears of homozygous genotypes of the female parent line and the male parent line. Step 5: Sow the single ears of homozygous maternal and paternal lines into ear rows for field phenotypic identification and screening. Selected ear rows are self-pollinated and tested after harvest. The kernels of the selected ear rows are tested for popping and screening. Finally, a number of maternal and paternal inbred lines of equal number are selected. Step 6: Cross the maternal inbred line and the paternal inbred line to obtain several hybrids; Step 7: Sow several hybrid varieties. Based on the standards in Step 5, conduct field phenotypic identification, indoor seed testing, and popping test on the five hybrid varieties. Based on the comprehensive identification results, select one hybrid variety to cultivate a popped corn variety for Korean-style corn popping.

2. The breeding method for puffed corn for Korean-style popcorn according to claim 1, characterized in that, In step 1, the parents selected were the popcorn single cross 'Jiaqiu 105' and the semi-dent corn single cross 'Tieyan 388'.

3. The breeding method for puffed corn for Korean-style popcorn according to claim 1, characterized in that, In step 1, the parents selected were the popcorn single cross 'Jiaqiu 105' and the flint corn single cross 'Demeya 1'.

4. The breeding method for puffed corn for Korean-style popcorn according to claim 1, characterized in that, In step 1, the parents selected were the popcorn single cross 'Jiaqiu 140' and the semi-dent corn single cross 'Shendan 10'.

5. The breeding method for puffed corn for Korean-style popcorn according to claim 1, characterized in that, In step 5, when conducting field phenotypic identification and screening, select plants whose plant shape and tassel branching are between those of the two parents, and whose stress resistance, robustness, and leaf color are more similar to the non-popcorn parent.

6. The breeding method for puffed corn for Korean-style popcorn according to claim 1, characterized in that, In step 5, the following criteria are used for seed selection: long cylindrical ear shape, 14-16 rows per ear, 100-kernel weight of 24-28 grams, embryo size accounting for 2-4% of the total kernel size, corneous endosperm accounting for 92-96% of the total endosperm, growth period of 120-130 days, compact or semi-compact plant shape, zero natural field incidence of stalk rot, head smut, head smut, and ear grain rot, and lodging rate of less than 5%; the selection criteria for popcorn are large popcorn, round popcorn shape, light corn color, and crispy taste.

7. The breeding method for puffed corn for Korean-style popcorn according to claim 1, characterized in that, In step 5, a sealed high-pressure popcorn popper is used for popping the popcorn.

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