陆地棉杂交组合F1、F2苗期优势表现及亲本配合力分析

【目的】筛选优异亲本和强优势杂交组合选育,为棉花F₂生产应用提供理论依据。【方法】以8个核背景不同的陆地棉材料为亲本,采用5×3的NCⅡ遗传交配设计,在大田环境条件下,测定亲本、F₁、F₂和对照品种苗期株高、叶片SPAD值和光合作用参数。【结果】株高、SPAD值和净光合速率的广义遗传力和狭义遗传力较高,部分性状的F₂遗传力高于F₁。苗期各性状一般配合力好的亲本为P₁(中901)、P₂(ZB)、P₆(大桃)和P₇(Z98);杂交组合F₁和F₂在苗期性状(株高、SPAD值、净光合速率、气孔导度、胞间CO₂浓度、蒸腾速率)中特殊配合力表现较好的为组合2(中901×Z98)、组合5(ZB×Z98)、组合7(SJ48×DT)。15个杂交组合的F₁和F₂在苗期各性状中较对照表现出不同的竞争优势,...

Heterosis Performance and Their Parental Combining Ability Analysis of F1 and F2 Hybrids of Upland Cotton at Seedling Stage

【Objective】 The purpose of this study is to provide theoretical foundation for the selection of superior parents, hybrid combinations and F₂ of cotton product application. 【Method】 Eight parents from areas of Yellow River, Yangtze River and Northwest Inland were divided into two groups of 5 or 3 respectively, and made crosses according to NCⅡ design of the incomplete diallel cross (5×3); The plant height, leaf seedling SPAD values, and photosynthesis parameters of the parental, F₁, F₂ and control varieties were determined under field environmental conditions. 【Result】 The results showed that, both broad sense heritability and narrow sense hetriability in plant height, SPAD, photosynthetic parameter were relatively high and some traits of F₂ heritability was higher than that of F₁ in seeding stage. Every trait of the parent with best general combining ability(GCA) were P₁(Zhong 901), P₂(ZB), P₆(DT) and P₇(Z98) in seeding stage. The hybrid F₁ and F₂ which showed better special combining ability in each character at seedling stage were combination 2(Zhong901×Z98), combination 5(ZB×Z98) and combination 7(SJ48×DT). The 15 hybrid combinations F₁ and F₂ showed different competitive advantages in seeding stage compared with the contol, and some combinations showed significant differences. Mostly combinations of F₁ and F₂ showed positive heterosis advantage with competitive advantage, the mid-parent and high-parent in plant height, SPAD value, net photosynthetic rate and stomatal conductance, but in others traits, F₁ and F₂ combinations showed negative heterosis advantage with mid-parent and high-parent. 【Conclusion】 In this study, based on breeding practice of hybrid cotton varieties, the heterosis performance and combining ability in different generations of traits at seedling stage are systematically analyzed. It is found that the hybrid combination composed of the male parent P₇ (Z98) group performs better than other combinations in the seedling stage traits and has a greater utilization potential.