水稻单胚多芽突变体4001的萌发形态及其遗传分析

对水稻品系4001成熟种子解剖和萌发形态观察，结果表明：4001的颖果内只有一个胚，但萌发时却出现多个芽的现象，为一份单胚多芽突变体水稻种质。其中58.9%的种胚具有多个芽鞘，萌发时出现多芽，多芽鞘胚缺乏鳞片，且外胚叶短小或缺失，从而导致芽鞘半裸露；芽鞘形态多样，以“掌状”和“卷舌状”等形状为多。4001萌发产生的多芽中有79.1%的是多芽多芽鞘（最主要为2芽2鞘），其余的是多芽共一鞘，少数共用一个芽鞘的多芽还表现共用第一叶和第二叶的现象；多芽在大小和生长速度上无主次之分；共一鞘的多芽之间有维管束联系，但不同鞘的芽间没有维管束联系，因此4001中的一籽多芽既不是主芽和次芽，也不是所谓的主芽和蘖芽。4001多芽的遗传复杂,推测可能是由于转座基因突变引起。

Germination Pattern and Genetic Analysis of Rice Mutant 4001 with Multiple Buds in Single Embyro

To clarify the causes of formation of multiple buds in rice mutant 4001,anatomy and morphological observation of mature seeds germination were conducted （ METHOD ） The number of grains within the embryo was checked with Olympus Endoscopic anatomy and their images were obtained by HP670 scanner.The results showed： the kernel of rice line 4001 had only one embryo but produced multiple buds after germination,indicating that 4001 was a novel mutant with multiple buds originated from the same embryo.58.9% of embryos had coleoptiles and consequently germinated multiple buds.Multi-coleoptile embryo lacked scales and ectodermals were short or absent,resulting coleoptiles half-naked.Coleoptiles morphology diverse and mainly was consisted of palmateand rolling tongueshape ones.Of multiple buds of 4001,79.1% were multi-bud and-coleoptile morphology （mainly bud and-coleoptile one）,the other was multi-bud of a coleoptile.A small number of multiple buds from a coleoptile were also observed to be enclosed by the first and second leaf commonly.Multi-buds were similar in size and growth speed.Multiple buds from a coleoptile were linked by vascular,while those from different coleoptiles were not.Thus,multiple buds of 4001 seed were neither primary and secondary buds,nor the so-called primary shoot and tiller buds.Multiple buds of 4001 were controlled by complex genetic mechanism and might be due to gene mutations caused by transposition.