Breeding method for cultivating japonica rice variety capable of efficiently utilizing nitrogen

Abstract

The invention discloses a breeding method for cultivating a japonica rice variety capable of efficiently utilizing nitrogen. The breeding method comprises the following steps: an early-growing and quick-sprouting spike-grain compatible type japonica rice variety serving as a female parent and a spike-grain compatible type japonica rice variety serving as a male parent are hybridized, sparse direct sowing planting is carried out on F0-F3 generations, and mixed- harvesting seed reserving is carried out; generations of F4 and above are sparsely sown for seedling raising, single-parent transplanting planting is conducted, and single-harvesting seed reserving is carried out. Nitrogen is reduced through a seedling fertilizer and a base-tiller fertilizer, the average stem tiller number of a single plant 25-30 days after sowing and the average ear number of the single plant in the mature period serve as selection pressure, strains are established according to a pedigree method F5, and optimization is carried out until a stable strain is obtained and promoted to participate in each stage of intermediate tests. According to the japonica rice variety cultivated through the method, under the condition that nitrogen is greatly reduced through the seedling fertilizer and the base-tiller fertilizer, strong seedlings can be cultivated, early growth and rapid germination are achieved, it is ensured that the suitable stem tillering number is obtained in the effective tillering stage, and finally, the purposes of fertilizer reduction, pesticide reduction, quality improvement and efficiency improvement in rice production are achieved.

Description

technical field [0001] The invention relates to the field of breeding methods, in particular to a breeding method for cultivating japonica rice varieties with high nitrogen utilization. Background technique [0002] Nitrogen, phosphorus, and potassium are macroelements necessary for the growth and development of rice, especially nitrogen, which is applied in the largest amount throughout the life of rice. In the middle and lower reaches of the Yangtze River, the yield per mu of japonica rice is 600kg, and the amount of nitrogen used is generally 18-20kg / mu. Then increase again and again. Although applying more nitrogen fertilizers is conducive to high and super high yields, with the increase of nitrogen input level, the effect of increasing nitrogen production and the input-output ratio are constantly declining. In addition, because the nitrogen use rate is only 30%-35%, Excessive and lost nitrogen can easily lead to eutrophication of water bodies, resulting in large-scale...

AI Technical Summary

Problems solved by technology

[0006] Obviously, the reduction of nitrogen in rice seedling fertilizer and basal tiller fertilizer is not conducive to the cultivation of strong seedlings with tillers, early growth and rapid emergence of tillers, early enough seedlings and tillering into spikes, and is not conducive to high and stable yields.

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