不同杂交世代棉花纤维强度及主要经济性状的遗传研究

GENETIC RELATIONSHIPS BETWEEN FIBER STRENGTH AND MAJOR ECONOMIC CHARACTERS IN DIFFERENT GENERATIONS IN UPLAND COTTON

利用１３个不同类型的陆地棉品种（系）配制成１５个ＦⅠ杂种，再利用其二代（ＦⅠ＿２）配制成１２个二轮杂交种（ＦⅠ），并于１９９４年种植Ｐ、ＦⅠ＿１、ＦⅠ＿２、ＦⅠ＿３、ＦⅠ＿４、ＦⅡ＿１、ＦⅡ＿２７个世代，应用多元分析法，对各世代的纤维强度进行了遗传分析及与主要经济性状的相关分析、通径分析和灰色关联度分析，结果表明：比强度以加性效应遗传为主，显性和上位性效应不显著，狭义遗传力在３７．９７％～８１．５８％之间。亲本及一轮杂交组合中比强度与衣分或皮棉产量呈极显著负相关（ｒ＝－０．３９～－０．７６），二轮杂交组合比强度与２．５％跨长达显著正相关（ｒ＝０．４４），与衣分和皮棉产量呈不显著负相关，单铃重与强度多数世代中均无明显相关（ｒ＝－０．０５～－０．３１）。衣分与强度的负相关是引起皮棉与强度负相关的主要因素，通过二轮杂交后，这种负相关程度降低。

Fifteen crosses(FⅠ)were made using thirteen different types of parents,and twelve crosses(FⅡ)were made using FⅠ_2.Seven generations(P.F_1.F Ⅰ_2.FⅠ_3.FⅠ_4.FⅡ _1.FⅡ_2)were studied in 1994.The results indicated that for fiber strength additive was the major effects.dominane and epistasis effects were not significant,and heritability was 37.97%.58%.The correlation coefficients, path coefficients and gray relational grades of strength with lint percent,lint yield,2.5% span length and micronaire varied in different generations.Strength was significantly negatively correlated(r=-0.39-0.76)with lint percent or lint yield in parents and FⅠ,and was significantly positively correlated(r=0.44)with 2.5%span lenth and was not significantly negatively correlated (r=-0. 05 -0. 31 ) with lint percent and lint yield in FⅡ.The boll weight was not signficantly correlated with fibre strength in most generations.The negative correlation between lint yield and fibre strength was mainly caused by the negative correlation between lint percent and fibre strength,and the negative correlation decreated after two cycles of hybridization