Evaluation of Segregating Populations in Rice.
2008
Baqeri, Mohammad Mahdi
One of the most effective strategies for increasing rice yield or other field crops with no increase in area of culture is increasing the yield efficiency per unit area. A practical effort to achieve this goal is developing new genotypes by crossing and obtaining the genetic variation. In this study 461 lines of F5 and 26 F2 populations of first back cross ( F2BC1) were evaluated. The aim of this study, was to detect and selection the genotypes with desirable morphological and agronomical traits, such as medium plant height and suitable plant architecture, high yield, grian shutering tolerance, early maturity, suitable grain shape and acceptable aroma content. Seeds of F5 lines and F2BC1 populations were sown in wetbed nursery .In order to weed control in seed bed, Moulinet herbicide was applied at 2 leaves stage. Urea was also applied in 3 leaves stage as topdressing with rate of 20 grams per square meter. Transplanting of F5 lines in 3 rows 2.5m each with 20 × 20 cm. spacing and also F2BC1 populations, in 26 separate plots with 25 × 25 cm. spacing were done.It should be noted that single plant per hill were determined for both F5 and F2BC1 generations. All nessesary cares and agronomical practices were done. Preliminary selection were done through periodical field observations in different growth stages specially at tillering and anthesis. The final selection was done at grain filling stage and physiological ripening. On the basis of research targets, 25 pure lines and 258 single plants within F5 lines and 221 single plants among F2BC1 populations were selected.
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