Development and Breeding Utilization of New Varieties with Bollworm Resistance and Non-Toxic Kernel in Cotton (Gossypium hirsutum L.)

The kernel of cotton seed contains abundant unsaturated fatty acids and amino acids necessary for human body. The kernel of gossypol cultivars could not been used directly as raw materials for human edible oil and food owing to high concentration of gossypol. A island cotton variety hai 1 with a dominant glandless character was crossed firstly with Sumian No. 6, a upland cotton cultivar, then the F₁ was backcrossed with Sumian No. 6. Suxianwu 062, a new variety with a little gossypol kernel was developed in the backcrossed population. The utilization of Suxianwu 062 as a glandless parent, seven new glandless varieties controlled by Gl₂^e gene were developed through cotton polymerization breeding technique. The results of detection for free gossypol content indicated that kernels of four new varieties were appropriate for Chinese edible standard, as new germplasms with the lowest gossypol content until now public report, the value of Suxianwu 154 and Suxianwu 156 were 0.000197% and 0.000238% respectively. The identification for pest resistance, lint yield and fiber quality stated that the resistance of two little gossypol strains to bollworm were up to the highest level, meanwhile higher than Sikang No. 1, one cultivar with gossypol kernel and bollworm resistance. The average lint yield of Suxianwu 154 and Suxianwu 156 was 1473.98 kg.hm^-2, yield increased span was 9.03% higher than gossypol cultivars. Main factors of lint yield enhancement were the increase of boll number per plant and seed cotton weight per boll. Fiber quality of two little gossypol varieties surpassed the standard of common good quality II. Two little gossypol varieties with bollwom resistance provide cultivar support and germplasm storation for cotton to transform successfully to be grain,cotton,edible oil.