软枣猕猴桃果实生长发育的研究

Studies on the growth development of fruit of Actinidia arguta Planeh

软枣猕猴桃果实重量和体积同步增长 ,生长曲线为“双 S”型。果实发育期随着 TSS含量的升高 ,其硬度呈下降趋势 ,两者呈负相关。显微和超微结构观察表明 ,1)早期胚胎发育 :多心皮合生子房 ,通常具 2 3个心室 ,中轴胎座。中轴上着生大量倒生胚珠 ,单珠被 ,具珠被绒毡层。胚囊蓼型。受精后 ,初生胚乳核分裂先于合子。胚乳发育为细胞型。2 )果实 :果壁可人为地分为果皮、果肉和果心 3部分。果皮较薄 ,由 2～ 3层薄壁细胞组成 ,外表面光滑无毛 ,但覆有角质层 ,气孔分布于其中。果肉的大部分由薄壁细胞组成 ,分大、小两种细胞 ,小细胞含较多淀粉粒。果肉薄壁组织细胞还含有叶绿体及两种异细胞。果心由维管束和薄壁细胞组成 ,维管束不发达。 3)种子 :种皮外表面呈蜂窝状 ,种皮较硬 ,由两层细胞构成。线性直立胚 ,胚乳发达。

The weight and volume of fruit of Actinidia arguta Planeh increased synchronously,whose growth accorded with double “S” curve,and the growth curve of length and breadth was the shape of “S”. The fruit development of Actinidia arguta Planeh was studied by means of LM and EM.The results are as follows:1.Young embryo divelopment:The gamogastrous which was constituted by polycarpel generally contained sixteen loculuses;Many anatropous ovules lay in axile placenta;Unitegimy had integumentary tapetum;The embryo sac is of Polygonum type.After fertilization,the primary endosperm nucleus divides earlier than zygote.The endosperm development is of cellular type.2.Fruit wall:It consisted of pericarp,pulp and pith.The pericarp which contained 2 to 3 layers of parenchyma cells is thin.The outer surface covered by cuticle and having sunken somata is smooth and glabrous.Most of the pulp,which is made up of parenchyma cells,is differentiated into two types of cells.Small type of cells contained more starch grains whose hydrolyzation is one of the causes for fruits softening.Parenchyma cells in pulp contained chloroplast and two kinds of idioblasts which differed in contents-one is ubiquitous crystal,the other is red foccule stained with safranine.The fruit core included parenchyma cell and poorly developed vascular bundles.3.Seed:The seed coat is alveolate on the outer surface,is hard and composed of two cells.The embryo is linearly and straight.The endosperm is well developed,mainly contains stored protein.