小麦颖果合点细胞超微结构与籽粒灌浆的关系

 利用不同灌浆特性的 3个小麦品种 (系 )为材料 ,研究了小麦颖果合点细胞的超微结构与灌浆过程的关系。结果表明 ,合点细胞液泡中沉积的脂类和多糖对籽粒灌浆过程无明显的抑制作用。合点细胞内壁上脂类和木栓质积累的多少、出现的时间与灌浆进程、灌浆结束时间有直接关系。灌浆速率大小与品种特性有关。大粒型品种 (系 )鄂恩 1号和 95A 10的合点细胞内壁脂类和木栓质出现迟 ,数量少 ;而小粒型品种华麦 8号出现早 ,数量多。颖果发育慢和灌浆速率小是 95A 10籽粒不饱满的主要原因。合点细胞主要以质外体和共质体并存的方式运输养分 ,开花后 2 4d以共质体运输方式为主。

Relationship Between the Ultrastructure of Chalazal Cells in Caryopsis and Grain Filling of Wheat

Using 3 wheat cultivars ( Triticum aestivum L.), Een1, Huamai8 and 95A-10 with different grain filling characters, the relationship between the ultrastructure of chalazal cells in caryopsis and grain filling of wheat were studied. The results showed that the lipoid and polysaccharide deposited in the vacuoles of chalazal cells had no obvious inhibitory effect on the grain filling. There was a direct relationship between the proceeding and ending time of grain filling and the amount and appearing time of the lipoid and lignifed cork deposited on the intine of chalazal cells. There was a direct relationship between grain filling rate and cultivars characteristic. The appearing time of the lipoid and lignified cork deposited on the intine of chalazal cells in the cultivar with large grain(Een1 and 95A-10) was later than that in the cultivar with small grain(Huamai8), but the amount of deposition in the former was fewer than that in the latter. The main cause for the wrinkled grain of 95A-10 was the late development of caryopsis and low rate of grain filling. The transport of photoassimilates in chalazal cells was by coexistence of symplastic and apoplastic pathways. The symplastic pathway was the main transporting way after 24 d of flowering.