夏玉米籽粒发育过程中淀粉积累与粒重的关系

RELATIONSHIP BETWEEN STARCH ACCUMULATION AND GRAIN WEIGHT DURING GRAIN DEVELOPMENT OF SUMMER MAIZE

利用显微解剖和组织化学的方法,系统观察了夏玉米籽粒(颖果)发育过程中淀粉的分布与消长,结果表明:在成熟胚囊至原胚期,子房柄、子房壁、卵细胞、助细胞、中央细胞、合子、原胚及游离核胚乳中存在许多小球形淀粉粒,处于不断积累同时又不断被利用的状态,是碳水化合物的暂时性贮藏形式,对籽粒的器官建成起重要的营养作用。胚器官分化期,胚和胚乳中开始形成淀粉粒,随籽粒发育,其数量和体积逐渐增加,直到籽粒完全成熟。这些淀粉粒是碳水化合物的永久性贮藏形式,积累的先后顺序及充分程度与籽粒重量、品质密切相关。

Microanatomical and histochemical observation upon distribution and fluctuation of starch during grain development of summer maize (Zea mays L.) has revealed that (i) during the period from embryo sac maturing to early proembryo developing, a lot of tiny starch grains exist in the ovary stalk, ovary wall, egg cell, synergids, central cell, zygote, early proembryo and free nuclear endosperm, which are continually accumulated and comsumpted, serving a temporary form for starage of carbohydrates and providing nutrients to forming of organs; (ii) during the differentiation period of embryo organs, starch grains begin to occur in the embryo and endosperm, with developing of kernels, the quantity and bulk of starch grain are increased until kernel maturing; and (iii) the starch grains are the permanent store form of carbohydrates, and the sequence and degree of accumulating are closly correlated with kerne yield and quality.