Dual purpose pollenizer watermelons

Abstract

The application relates to the field of plant breeding, in particular watermelon breeding. Provided are diploid watermelon plants (and seeds from which these plants can be grown) which produce small, diploid, red watermelon fruits. Also provided are small, diploid watermelon fruits having an average weight of less than 1.8 kg.

Description

FIELD OF THE INVENTION[0001]The present invention relates to the field of watermelon breeding and watermelon improvement. Provided are new diploid watermelon plants (2n=2x=22) and seeds from which such plants can be grown, which produce very small diploid fruits. The diploid watermelon plants are preferably suitable as pollenizers in triploid watermelon (2n=3x=33) production, whereby the pollenizers therefore have a dual purpose: providing sufficient viable pollen to pollinate female flowers of triploid plants (which after pollination produce triploid, seedless watermelon fruits) and / or to provide small (“mini”- or personal size), edible diploid fruits on the pollinizer plants themselves.BACKGROUND OF THE INVENTION[0002]Seedless watermelon (Citrullus lanatus (Thunb.) Matsum. And Nak.) production involves using pollen from diploid male parent plants to fertilize flowers of tetraploid (2n=4x=44) maternal parent plants. Pollination of the tetraploid flowers with diploid pollen leads to...

AI Technical Summary

Benefits of technology

[0018]“Pollenizer plant” or “pollenizer” refers to the (inbred or hybrid) diploid plant, or parts thereof (e.g. its pollen or scion), suitable as pollenizer for inducing fruit set on triploid plants. A pollenizer plant is, thus, able to lead to good fruit set (and good triploid fruit yield) of triploid plants, by producing an appropriate amount of pollen at the appropriate day-time and for an appropriate period of time, e.g. at least during peak flowering time of the triploid female plants. A good triploid fruit yield is, for example, a yield comparable to the yield obtainable when using Polimax (produced by Nunhems) as pollenizer (see e.g. Example 3).

[0036]Other fruit characteristics can be introduced by traditional breeding methods (see further below) and thereby combined with pollenizers producing small, edible diploid fruits according to the invention. For example plants can be selected which produce small, edible fruits, as described above, with increased or reduced rind thickness, increased or reduced rind brittleness, various skin / rind colors (e.g. light green; dark green; green-striped with narrow, medium or wide stripes; grey types; with or without spotting; Golden yellow) and rind surfaces (e.g. furrowed or smooth surface), flesh structure / flesh firmness, different fruit shapes (elongate, oval, blocky, spherical or round), higher brix content, higher lycopene and / or vitamin content, different sugar:acid ratios, very good fruit flavour, etc. Also the combination of small edible fruits with another flesh color than red is possible, for example genetic determinants for yellow flesh or orange flesh or white flesh may be introduced, e.g. by backcross breeding with another color-type. See Guner and Wehner 2004, Hort Science 39(6): 1175-1182, in particular pages 1180-1181 describing genes for fruit characteristics. Generally important breeding objectives are early maturity, high fruit yield, high internal fruit quality (good uniform color, high sugar, proper sugar:acid ratio, good flavor, high vitamin and lycopene content, firm flesh texture, non-fibrous flesh texture, freedom from defects such as hollow heart, rind necrosis, blossom-end rot or cross stitch and good rind characteristics and cracking-resistance).

Problems solved by technology

Some pollenizers produce diploid fruits which could be marketable, while others produce fruits that are unsuitable for consumption and marketing.

The fruits of Sidekick are very poor quality pink-fleshed and those of SP-1 are white-fleshed and have a low brix value.