Resistant mechanisms viz., antixenosis, antibiosis, and tolerance of six cotton genotypes were evaluated under free-choice and no-choice conditions against Bemisia tabaci Asia-II-8. Results showed that the whiteflies select the host for oviposition after initial probing. The genotypes LRA-5166 and LHDP-1 was least preferred for oviposition under free-choice condition and lesser nymphal survival (47.50 and 52.50 per cent), net reproductive rate (R0) (5.45 and 6.31 nos./female/lifetime) and intrinsic rate of increase (rm) (0.061and 0.063) under no-choice condition, respectively and exhibited antixenosis and antibiosis resistance against whitefly. The genotype CCH-4474 demonstrated tolerance mechanism to whiteflies with less reduction in the plant height (20.77%), number of internodes (15.27%) and chlorophyll content (13.44%) over the control. The high level of resistance in the genotypes LRA-5166 and LHDP-1 can serve as the basis for the genetic improvement of cotton focusing on the development of B. tabaci resistant varieties.

中文翻译：

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棉花基因型对粉虱 Bemisia tabaci Asia-II-8 (Hemiptera: Aleyrodidae) 抗性机制的表征

在自由选择和非选择条件下评估了对烟粉虱 Asia-II-8 的六种棉花基因型的抗性机制，即抗排毒、抗菌和耐受性。结果表明，粉虱在初始探测后选择宿主进行产卵。基因型 LRA-5166 和 LHDP-1 在自由选择条件下最不喜欢产卵，若虫存活率较低（47.50% 和 52.50%）、净繁殖率（R0）（5.45 和 6.31 只/雌性/终生）和内在增加率（rm）（0.061和0.063）分别在无选择条件下表现出对粉虱的抗排毒和抗菌抗性。基因型 CCH-4474 表现出对粉虱的耐受机制，与对照相比，株高 (20.77%)、节间数 (15.27%) 和叶绿素含量 (13.44%) 减少较少。