陆地型长绒棉新种质F2代主要经济性状相关及通径分析

陆地型长绒棉亲本98301与高产亲本石远321杂交，对F2分离群体Len（2．5％跨长）、Un（纤维整齐度）、Str（束纤维拉力，g／tex）和Mic（麦克隆值）4个纤维品质性状及单株籽棉产量（霜前）、单株皮棉产量（霜前）、衣分、单株铃数（霜前收获铃数）、单铃重、籽指、青铃率7个产量性状间相关系数和通径系数进行分析。结果表明，Un与Str和Mic分别呈极显著正相关，Un与Len为显著负相关；Len与Str为极显著正相关；Str与Mic为负相关。Un与籽棉产量、皮棉产量、衣分和单株铃数间均呈极显著或显著正相关；Len与籽指、单铃重和青铃率间为正相关，而与衣分间为负相关；Str与籽指和青铃率之间为显著正相关；Mie与单株铃数和籽指间为正相关。通径分析表明，与皮棉产量有正向直接作用的性状是单株铃数〉单铃重〉衣分〉籽指。4个纤维品质性状中以Mic与皮棉产量间的负向直接作用最为重要，Str对皮棉产量直接作用为正值，它通过单株铃数、单铃重及Mic对产量的间接作用均为正值；Len通过单铃重和铃数对皮棉产量的正向间接作用有利于实现育种目标，而Len通过衣分对皮棉产量的负向间接作用在后代选择时应加以重视。

Correlation and Path Analysis on Main Economic Characters in F2 Generation of Upland Fine-fiber Cotton

The correlativity among 4 fibre characters,2.5% span length(Len),Uniformity(Un),Fibre strength(Str),micron value(Mic),and 7 yield characters,unginned cotton yield and lint yield per plant,lint percentage,bolls per plant,boll weight,seed index and immature boll rate before frost in F2 generation of 98301(with fine fiber)×Shiyuan 321(with high yield) were studied.In the results,the Un correlated positively with the Str and Mic significantly at 0.01 level and negatively with the Len significantly at 0.05 level.There was a significantly positive correlation at 0.01 level between the Len and Str,and significantly negative correlation at 0.05 level between the Str and Mic.The Un correlated positively with the unginned cotton yield,the lint yield,the lint percentage and bolls per plant significantly at 0.01 or 0.05 level.The Len was correlated positively to the seed index,boll weight and immature boll rate significantly at 0.01 or 0.05 level,and negatively to the lint percentage significantly at 0.01 level.The Str was correlated positively to the seed index and immature boll rate significantly at 0.05 level and the Mic was positively correlative with the bolls per plant and seed index significantly.The path analysis showed that there were positively direct effects of the bolls per plant,boll weight,lint percentage and seed index to the lint yield.A negatively direct effect of the Mic to the lint yield was most important among the fibre characters.The direct and indirect effects of Str through the bolls per plant and boll weight to the lint yield were positive,while the indirect effects of the Mic to the lint yield were also positive.The positive indirect effects of Len through bou weight and bolls per plant to the lint yield were favorable to achieving the breeding goal,and the negative indirect effects of Len through lint percentage to the lint yield should be paid more attention in the offspring selection.