小麥의 出穗後 日數에 따른 小穗段別 粒重의 品種間 差異

Varietal differences of kernel weight according to the positions of spikelet in different days after heading in wheat

This experiment was carried out to investigate the change of kernel weight and the position of spikelet with the highest kernel weight on the spike of wheat varieties at 25, 35 and 45 days after heading from Oct. 1985 to June 1986 in Suwon Korea. Among 14 varieties tested, Suwon 239, with the latest maturing time, has been highest kernel weight of 14.9g, followed by Olmil, Geurumil and Eunpamil at 25 days after heading. Increment of grain weight was the most between 26 and 35 days after heading. Geurumil and Milyang 26 have the hightest kernel weight increment of 25g and Milyang 25 has the lowest of 13g during this period. Between 36 and 45 days after heading, however, Milyang 25 has much grain weight increment of 15g, followed by Suwon 242, Suwon 241 and Tapdongmil while Eunpamil and Olmil have very little increment in this period. There are three patterns of grain filling process. First, Suwon 242 and Milyang 25 show slow and progressive grain filling pattern from early to late period. Second, Eunpamil, Olmil and Suwon 239 which have lightier kernel weight of 34 to 37g show rapid grain filling patteren, nearly completing accumulation process by 35 days after heading. Third, the other varieties show that most of accumulating process was made between 26 and 35 days after heading but some process was continued untill even later period. Highly positive quadratic regression coefficient was between the position of spikelet on the spike and kernel weight, thus upper and lower part of spike having lighter kernel and middle part of spike, heavier kernel which were in the 8th to 10th spikelet on the spike.