ABSTRACT

To understand the effect of heat stress on morphology and physiology of the cotton, eight cotton genotypes with their 15F1 hybrids (five lines, three testers) were grown in the field conditions under randomized complete block design (RCBD) with two treatments i.e. normal and high-temperature stresses with two replications followed by split-plot arrangement. Data were collected for biochemical and yield-related parameters. Mean values of all studied traits were reduced significantly under high-temperature stress whilst the mean value of lint%, catalase activity, total soluble proteins, peroxidase, and carotenoids were increased under high-temperature. Under both conditions, the number of bolls, boll weight, seed cotton yield, lint index, seed mass per boll, hydrogen peroxide content, catalase activity, total soluble proteins, carotenoids, and chlorophyll contents had high heritability values along with high genetic advance percent mean which revealed, these traits were controlled by additive gene action. The lint%, seed index, short fiber index, fiber strength, fiber fineness, upper half mean length and peroxidase activity had high heritability with moderate genetic advance under heat stress conditions which showed, these traits were controlled by non-additive gene action. Under both temperature conditions, FH-458, IUB-65, CRS-2, and FH-313 were good general combiners for physicochemical and yield-related traits. The cross combination of IUB-013× CRS-2 and FH-458× FH-313 were good specific combiner for plant height and seed cotton yield whilst for fiber quality and biochemical traits, the best specific combiners were VH-329× FH-313 and IUB-013× CRS-2. These identified parents and cross combinations might be used for improving already present commercial varieties under high-temperature stress.

摘要

为了解热应激对棉花形态和生理的影响，采用随机完全区组设计 (RCBD) 两种处理即正常和高浓度，在田间条件下种植了 8 个棉花基因型及其 15F1 杂种（5 个品系，3 个测试者）。 - 两次重复的温度应力，然后是裂区排列。收集生化和产量相关参数的数据。所有研究性状的平均值在高温胁迫下显着降低，而皮棉百分比、过氧化氢酶活性、总可溶性蛋白、过氧化物酶和类胡萝卜素的平均值在高温下增加。在这两种条件下，棉铃数、铃重、籽棉产量、皮棉指数、每铃种子质量、过氧化氢含量、过氧化氢酶活性、总可溶性蛋白质、类胡萝卜素、和叶绿素含量具有较高的遗传力值以及较高的遗传提前百分比平均值，这表明这些性状受加性基因作用的控制。在热胁迫条件下，衣分、种子指数、短纤维指数、纤维强度、纤维细度、上半部平均长度和过氧化物酶活性具有较高的遗传力，且遗传进展适中，表明这些性状受非加性基因作用的控制。在两种温度条件下，FH-458、IUB-65、CRS-2 和 FH-313 都是理化和产量相关性状的良好通用组合。IUB-013×CRS-2和FH-458×FH-313的杂交组合在株高和籽棉产量方面具有较好的特异性结合剂，而在纤维品质和生化性状方面，最佳的特异性结合剂是VH-329×FH-313和 IUB-013× CRS-2。