Hybrid Watermelon Introduction Watermelon [Citruses landaus] is an important fruit crop of the world. Hybrid varieties (an, an) are now fast replacing open-pollinated cultivar. In Japan, for example, between 1958 and 1987, of the 125 watermelon varieties released, all but one was hybrids. In China and the USA also, hybrids occupy the largest watermelon acreage. The wide acceptability of hybrid varieties is due to higher yield, better quality, fruit uniformity, good storage, and disease resistance.
As most of the hybrid seed in this largely unconscious crop is produced by flower isolation and manual alienation, the cost of hybrid seed is 10 and 100 (for an and an respectively) times higher than for open-pollinated seed. Seedless Watermelon Seedless watermelon (an) is superior to diploid watermelon as it combines the advantages of polyploidy and hoteliers per SE. It has, in general, a high soluble solid matter content, disease resistance and yield. For the production of triploid hybrid watermelon, the spontaneously developed or induced triploids(xx; an=44) are crossed with the diploid (xx; an=22) parent.
The triploid plants can be easily identified due to slower seedling growth rate, thick stem, larger leaves, and flowers. A good triploid watermelon hybrid must have high seed germination, strong growing vigor, good fruit setting and high yield. Pollination Control Mechanism * Artificial Pollination Watermelon is a discussions plant with large flowers, and hence artificial pollination control is easy. At the time of flowering, the male flowers are removed from the plant and female flowers are isolated. The pollen collected from the desired male parent can be used to pollinate isolated female flowers.
Staminate Flower Control Watermelon produces both staminate and pastille flowers. The staminate flowers are first to appear followed by the pastille. Hybrid seed yield can be increased substantially by controlling the number of staminate flowers. The chemicals like typhoon, naphthalene acetic acid, GAG and 2-3-disproportional acid can control staminate flowers if applied before initiation of flowering. * Chemical Hybridism Agents Male sterility could be induced in this crop following pre-antithesis application of malefic hydrazine and Mended.
Chemicals, however, have not been found to be suitable for inducing transient male sterility as they adversely affect female fertility and vegetative growth. Types of Hybrids Two types of hybrids are generally produced in watermelon. 1 . Single-Cross Hybrid. This is a hybrid of two parent lines. This type of hybrid has strong hoteliers, uniform and standardized growth; its seed production is simple as two parent’s can be maintained easily. This single-cross variety is the main form of watermelon hoteliers breeding, as in the Sing Change, Hong You, UP hybrids in China. 2.
Double-Cross Hybrid. This variety is a hybrid of two single-cross varieties which is produced from four sealed lines. The double-cross variety has very strong adeptness’s and a rich genetic base. Seed production is complex, as four inbreeds are required to be maintained Examples Name: Watermelon, Hybrid Diploid Red Flesh WAD-02-29 Type. Conclusions Hybrids in watermelon are becoming popular throughout the world. However, their further adoption in Asia and Africa will largely depend upon our ability to reduce seed production costs, especially for seedless watermelon hybrids.