بررسی و انتخاب در توده ها و نسلهای در حال تفکیک گندم نان و آزمایش مقایسه عملکرد مقدماتی

Segregation of traits in hybrids of bread wheat begins from F2 population and continues until several generations later. At first, the best combinations of hybrids were selected and then from among of them base of traits: plant height, strong tillers, unity of tillers, spike form, resistance to shattering, suitable leaf angle, resistance to preharvest sprouting and reaction to diseases such as yellow rust, leaf rust, powdery mildew, septaria leaf blotch and scab were selected individual plant. In this study, in F2 generation 342 population, F3 generation 271 numbers, f4 generation 359, F5 generation 247, F6 generation 219 and F7 generation 429 numbers of bread wheat evaluated in modifi'ed pedigree-bulk method. At first, from among of F2 generation were selected 2399 individual plant base of morphological traits in the field, then thrashing and discarding the shriveled seeds. The seeds remain from each number bulked together that they were 243 numbers for F3 generation. In F3, F4, F5 and F6 generations suitable individual plants for each number in the field were selected. Number of plants for F3, F4, F5, and F6 were 2510, 1980,692 and 558 respectively. After thrashing and discarding the shriveled seeds, remain seeds for each number bulked together for F3 and F4 generation finally 243, 228 numbers for F7 respectively base of pedigree method. In F7 generation after checking all of plants, 175 numbers of them that were the best for all traits were selected. After thrashing and checking finally all of 151 pure lines were selected for studying in 1384-1385 preliminary tests. In this study 128 bread wheat lines from Gorgan crosses in 1382-1383 year were planted with Tajan, Shiroudy and N-75-16. Area of each plot was 7.2 m2. Morphological and agronomy traits and reaction of lines to leaf diseases were measured. Selection of lines did based on seed yield and morphological traits and reactions to diseases. Finally, 55numbers of the best lines were selected to evaluate in the PRWYT experiment in 1384-1385 year. Key words: bread wheat, selection in the segregation generations, preliminary test.

Keywords:

نسل های در حال تفکیک , گندم نان , مقایسه عملکرد , ریزش دانه , زنگ زرد , زنگ قهوه ای , سفیدک پودری , سپتوریوز برگ , فوزاریوم