苦荞杂交后代株型性状和产量性状的遗传分析

Genetic analysis on plant type traits and yield traits in tartary buckwheat hybrid progeny

  • 摘要: 【目的】 对苦荞杂交后代株型性状和产量性状进行遗传分析,为矮秆苦荞新品种培育提供良好的理论依据。【方法】 以株高差异较大的2个苦荞品种杂交F2和F3代群体为研究对象,分析其株高、主茎节数、一级分枝数、二级分枝数、茎粗、单株粒数、单株粒重和千粒重8个农艺性状的遗传规律,并对性状间的相关性进行分析。【结果】 8个农艺性状在F2和F3群体中均出现超亲分离;主茎节数和千粒重的变异系数小于20.00%,单株粒数和单株粒重的变异系数大于50.00%,其他性状的变异系数为20.00%~40.00%。株高、主茎节数、单株粒数和单株粒重的加性方差小于显性方差,平均显性度均大于1.00;一级分枝数、二级分枝数、茎粗和千粒重的显性方差小于加性方差,平均显性度小于1.00。千粒重的狭义遗传率、广义遗传率和固定遗传率均大于其他性状。F3代群体农艺性状间相关分析结果显示,株高和单株粒重均与单株粒数、千粒重、主茎节数、一级分枝数、二级分枝数和茎粗存在极显著正相关(P<0.01、P<0.001)。筛选出13个株高比母本矮、单株粒数和单株粒重比母本多的优良单株,其中有3个单株的株高比母本矮50 cm及以上。13个优良单株的农艺性状间相关分析结果显示,株高与主茎节数存在极显著正相关(P<0.01),单株粒重与茎粗、单株粒数存在极显著正相关(P<0.001),株高和单株粒重均与其他性状无显著相关(P>0.05)。【结论】 苦荞矮秆高产育种过程中,由于千粒重与其他性状相关系数较小,且具有较高遗传率,可在杂交初期世代进行单株选择;株高与其他主要农艺性状存在显著或极显著正相关,则需要综合考虑性状间的相关性进行单株选择,才能达到选育高产矮秆苦荞品种的目的。

     

    Abstract: 【Objective】 The study aimed to conduct a genetic analysis of plant type traits and yield traits in tartary buckwheat hybrid progeny,providing theoretical basis for the cultivation of new dwarf tartary buckwheat varieties. 【Method】 The study focused on the F2 and F3 generation populations of hybrid progeny from 2 tartary buckwheat varieties with great differences in plant height. The genetic patterns of 8 agronomic traits were analyzed,including plant height, node number of main stem,number of first branches,number of secondary branches,stem diameter,number of seeds per plant,seed weight per plant,and thousand-kernel weight,along with the analysis of the correlation among these traits. 【Result】 The 8 agronomic traits exhibited superparental segregation in both F2 and F3 populations. The coefficients of variation for node number of main stem and thousand-kernel weight were less than 20.00%,while the coefficients for the number of seeds per plant and seed weight per plant were greater than 50.00%. The coefficients for all other traits ranged from 20.00% to 40.00%. The additive variance for plant height,node number of main stem,number of seeds per plant and seed weight per plant was less than the dominant variance,with a mean degree of dominance greater than 1.00. Conversely,for the number of first branches,number of second branches,stem diameter and thousand-kernel weight, the dominant variance was less than the additive variance,resulting in a mean degree of dominance less than 1.00. In this case,the narrow sense heritability,broad sense heritability and fixed heritability of thousand-kernel weight were greater than those of the other traits. Correlation analysis among agronomic traits in the F3 generation population revealed that both plant height and seed weight per plant were extremely significantly and positively correlated with number of seeds per plant,thousand-kernel weight,node number of main stem,number of first branches,number of secondary branches and stem diameter(P<0.01,P<0.001). A total of 13 superior lines were identified which were shorter than the female parent and had a greater number of seeds per plant and seed weight per plant than the female parent,with 3 lines being at least 50 cm shorter than the female parent. Correlation analysis among the agronomic traits of the 13 superior lines revealed extremely significant positive correlation between plant height and the node number of main stem(P<0.01),and extremely significant positive correlation between seed weight per plant and both stem diameter and number of seeds per plant(P<0.001). Both plant height and seed weight per plant were not significantly correlated with the other traits(P0.05). 【Conclusion】 In the breeding process for high-yield dwarf tartary buckwheat,thousand-kernel weight has a low correlation coefficient with other traits and exhibits high heritability,allowing for single-plant selection in the early generations of hybridization. However,since plant height shows significant or extremely significant positive correlation with other main agronomic traits,it is necessary to comprehensively consider the correlations among traits during single-plant selection to achieve the optimal selection target for high-yield dwarf tartary buckwheat.

     

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