Studies on high yielding ability in wheat [Triticum aestivum]: Varietal differences in yield and yield component
1998
Toyota, M. (Kagawa Univ., Miki (Japan). Faculty of Agriculture) | Iwai, T. | Kusutani, A. | Asanuma, K.
The differences in yields and yield components of 117 wheat cultivars inclusive of 30 Japanese cultivars, 24 foreign cultivars, and 63 Japanese breeding lines were analyzed. Yield were varied from 27.3 g/row to 240.4 g/row, and its coefficient of variation (CV) was 30.4%. CV were 30.3% for total grain number and 9.5% for thousand grain weight. Total grain number had closely positive correlation with yield, whereas there was no significant relationship between thousand grain weight and yield. This means that the sink not the source was the limiting factor of yield for these tested cultivars, although there was significant positive correlation between thousand grain weight and yield for cultivars which had 4000 grain/row or higher of total grain number. We regarded the ratio of grain number per spike/spike number as an index of grain productive structure and divided all cultivars into 3 types, i.e. grain number per spike type(GN type), middle type and spike number type (SN type). Most foreign cultivars belonged to SN type, and most Japanese breeding lines belonged to middle type and GN type. Total grain number of GN type and SN type were relatively smaller because grain number per spike of spike number was limited, whereas middle type had well proportioned grain number per spike and spike number, resulting significantly higher total grain number and yield than other two types. These results suggest that the yield component as the breeding objective have to be decided considering grain productive structure type individually
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