Assessment of genetic variation among two cotton varieties Giza 80 and Giza 83 with their off-types [electronic resource].

Includes references.

The two Egyptian cotton varieties Giza 80 and Giza 83 were cultivated in a large scale of Middle and South Valley, respectively. "Recently, area of G. 83 gradually is shrunk". Several observable off-type plants, which cause reduction in yield and inferior in fiber-quality, were characterized, grouped and evaluated throughout three successive seasons at Sids Agricultural Research Station. This investigation was conducted to gain insight into genetic variability between the standard types and their off-type patterns. The results showed that the differences among G. 80 and G. 83 with their off-type patterns were mainly, affected by two factors. The first one was attributed to the cultivars and their off-type groups, while the second factor concerned the ability of characters that might exhibit discrimination. Canonical discriminant analysis revealed that the lint percentage character showed highest discrimination among studied varieties and their off-type groups. The other discriminant traits; lint index, seed index, boll weight, micronaire value and pressely index gave unconventional behavior according to the cultivar. While, seed cotton yield/plant, lint yield/plant, boll number and number of seeds/boll characters exhibited minor effect, so that they might not be used as indicator for genetic differentiation among studied genotypes. The squared distances (02 ) between G. 80 and both of G. 80 T1 (dark creamy lint naked seeds) and G. 80 T2 (light creamy lint tufted seeds) were highest than the other two off-type groups, indicating the mixture by these off-type seeds in some general farms of G. 80. With respect to G. 83 and its off-type groups, G. 83 T1 (white lint-naked seeds) exhibited longer genetic divergence comparable to the others.

Summary in Arabic.

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