Comparative Genetic Studies on Some Off-Type Cotton Plants of Giza 80 Cultivar and Their Effects on Varietal Deterioration

Abstract

The present work was conducted at Agricultural Research Station of Sids during the two seasons, 2008 and 2009. The materials used included the off-type plants derived from the Egyptian cotton variety Giza 80 which cultivated in a large scale of the Middle Egypt to study some of their economic traits and their effects in reducing yield and lint quality of Giza 80. Giza 80 variety as well as its off-type plants were characterized in the field and in the laboratory, growth habits, fruiting behavior yield and yield components, intensity of fuzz distribution on the seeds and fiber properties. Also, the RAPD technique was used as a tool for setting up a convenient and standard protocol to determine the difference and variation between plants of the variety Giza 80 and its off-type plants.Field characterization of the off-types showed, taller plants, longer leaves, different boll shapes and intensity of fuzz distribution on the seeds as compared to their standard type Giza 80. The results showed that the off-type plants of Giza 80 gave considerably lower values for boll weight, seed cotton yield,