棉花杂种一代与二代的优势比较及性状相关分析

HETEROSIS AND CORRELATION oF F_1 AND F_2 HYBRIDS IN COTTON

利用具有棉属野生种和半野生种族系血统的种质系与陆地棉品种杂交的5个组合F_1和6个组合F_2为材料,分析了F_1和F_2的皮棉产量,产量构成因素和纤维品质的竞争优势,F_1和F_2性状表型值的相关和F_2的优势降低率。结果表明:F_1和F_2的皮棉产量竞争优势分别为12.4%和5.2%。在产量构成因素中,增加单株结铃数对产量影响最大,衣分次之,有些组合中增加铃重有重要作用。F_1和F_2的纤维品质差异不明显。因组合不同,F_1和F_2的增产潜力差异较大,少数组合F_2仍具有一定利用价值;F_1和F_2性状表型值具有不同程度的正相关,其中以衣分、衣指、绒长和僵瓣率的相关性较高,达显著或极显著水平;F_2的产量和构成产量因素的衰退比纤维品质明显。

Five F_1 and six F_2 combinations were made by crossing two cultivars and five stocks which were related to wild species of Gossypium and semi-cultivars of G. hirsutum race. The competitive heterosis, the correlations of F_2 and F_1, and the inbreeding depression were evaluated by lint yield. yield characters and fiher qhalities. The results indacated that the competitive heterosis of F_1 and F_2 in lint yield was 12.4% and 5.2% respectively. With regard to yield characters, the number of boll per plant was most important to yield in all combinations. while average boll weight was also important in a few combinations. There was no obvious difference between F_1 and F_2 in fiber qualities. It was noted that there was great difference in yield potential among combinations of F_1 and F_2. A few of the F_2 cobinatlons possessed a certain extent of heterosis which can be used in production. There were positive correlations between F_1 and F_2 on measured characters. The fiber percentage, lint indwx and 2.5% span length were significantly correlated between F_1 and F_2.