Hetrosis and some genetic parameters in two intraspecific crosses of Egyptian cotton [electronic resource].

Includes reference.

The main objec lives of the present research were to estimate heterosis, inbreeding depression, potence" lio and some genetic parameters, Le., gene action, and heritability in both broad and narrow senses. The six populations P₁ P₂ F₁ F₂ BC₁ and BC₂ were grown during 2005 season in randomized complete block design. The results could be summarized as follow: (1) Cross I ( Giza 45x Giza 70) revealed significant heterosis relalive to mid-parent for no. of harvested bolls/plant, seed cotton yield/plant and lint yield/plant whereas relative to better parent for boll weight ,lint yield/plant lint index and no. of seeds/boll. Cross II(Giza 76 x Giza 75} showed also significant heterosis relative to mid parent or to better parent for all studied traits except lint percentage, seed index and no. of seeds/boll , (2) Inbreeding depression recorded significant values in five traits for cross I whereas differed significantly in all studied traits except one i.e., lint percentage for cross II, (3) Potence ratio values showed that over dominance control for the no. of harvested bolls/plant, in cross I. Also, this over dominance was observed in cross II for all studied characters, Six traits recorded positive potence ratio exceeded the unit(4) Scaling test parameters differed significantly for most studied traits in two intraspeciific crosses. A parameter differed significantly for all studied traits except lint percentage, lint index and no. of seeds/boll in cross I and except seed cotton yield/plant and lint yield/plant for cross II. B parameters deviated significantly than zero in cross I .or all studied traits except, lint percentage in cross I and except boll weight and lint percen age for cross II, (5) Dominance effect differed significantly for all traits,except lint percentage in cross I and no. of seeds/boll in cross II, (6) Additive effect showed highly significant values in four traits in cross I in addition to boll weight and seed index in cross II, (7) Gene interaction recorded significant positive or negative values for most traits of both crosses, (8) heritability values in broad sense, were over 50% for all studied traits in cross I, except both lint index and no. of seeds/boll. With regard to cross II no, of harvested bolls/plant, boll weight, seed cotton yield /plant exceeded 50%. Narrow sense values were differed from low values, moderate to high values for all studied traits .

Summary in Arabic.

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