陆地棉与海岛棉种间杂种产量品质优势的研究

Heterosis of Yield and Fiber Performance in Interspecific Crosses be-tween Gossypium hirsutum and G. barbadense

本研究探讨陆地棉与海岛棉种间杂种在长江中游棉区的杂种优势表现。试验涉及１０个陆地棉亲本和１０个海岛棉亲本及其３３个杂种，分别于１９８９年（１６个杂种）、１９９１年（９个杂种）和１９９２年（８个杂种）进行。陆地棉种问杂种的产量、铃数、子指、株高和纤维品质的中亲优势十分明显，与双亲平均值比较，皮棉产量平均高出８３．８％，成铃数增加３９．９％。但与陆地棉对照品种比较；种间杂种产量严重降低，平均下降３２．８％。陆海杂种结铃性强，成铃数比对照高出８６．１％，但许多青铃在后期不能正常成熟。采用早熟陆地棉与适应性较好的海岛棉杂交，产量下降幅度小，在秋季雨水少、降温迟的年份甚至出现增产的少数组合。大多数种间杂种纤维长度＞３４ｍｍ，比强度＞２５ｇ／ｔｅｘ，麦克隆值＜３．７，中亲优势均超过１０％，大多数杂种竞争优势超过１５％，甚至优于海岛棉，表现超显性遗传，而纤维整齐度降低幅度很小（－１．２％）。

Tests for yield, yield components and fiber properties in intersnecific crosses of G.hirsutum and G. barbadense were conducted in l989,1991 and l992.Ten cultivars for each ofthose allotetraploid species and 33 interspecific hybrids were involved.The average magnitudeof mid一parent heterosis for lint yield and number of bolls was 83.6%and 39.9%, respective-ly. The marked reduction (32.8%)in fiber yield of the hybrids, as compared with a commer-cial upland cotton, was associated in all cases with negative heterosis for lint percent(-18.6%)and for boll weight(-31.2%).The interspecific hybrids produced more bolls than up-land cotton cultivars and many green bolls of them did not matured normally. A few crossesbetween the earlymaturing upland cottons and the adapted G. barbadense entries had desirableyield potential. Most of interspecific crosses produced long( > 34mm),strong(> 25g/tex)and fine(<3. 7) fibers,displaying significant overdominance. Fiber uniformity of the interspe-cific hybrids only showed slightly decrease.