بررسی اصلاح لاینهای متحمل به شوری در پنبه الیاف متوسط به روش تلاقی برگشتی

In this project in order to increase salt-tolerant of commercial cultivars, those lines were used that selected from saline lands of sadoddin cotton farms in Kashmar. These lines possessed high growth ability under saline stress with small boll growth size. In order to improve salt-tolerant lines with upstanding vegetative growth under salt stress conditions, crossing were done between commercial cultivars namely, Varamin, Sahel, Bakhtegan and Mehr and selected lines. This followed by several back crossing at Varamin station and screening of offspring under saline condition at Sadoddin station at the next of each year. This operation repeated during 4 years and in the last year several elite plants were selected from both stress (kashmar) and non-stress (varamin) of salinity. The results reveal that average value of measured traits of selected lines were superier than their commercial parents under both conditions of stress and non-stress of salinity. For example, average seed cotton plant yield of improved lines which derived from Mehr cultivar crosses was 109.9 gr, while under salt stress conditions the same in Mehr cultivar was 55.3 gr. Also under non-salt stress condition, average seed cotton of these lines was 145.9 gr but in their maternal parent (cv. Mehr) it was 108 gr. The main conclusions describe that resulted populations from crosses posses some economically significant traits, especially under salt stress conditions which made them superior than their parents and such a large generated diversity could be used for elite genotypes in further breeding researches.

Keywords:

پنبه , ارقام , تحمل نمک , تلاقی برگشتی , روش های زادگیری