冬小麦种子的发育及其田间活力

１９９３－１９９４年北京对六冬小麦品种籽粒发育程度及不同发育程度籽粒的发芽力、活力进行了研究。从花后５天开始每３天取样一次，测定籽粒的干重，观察了其中两种材料发育早期籽粒种胚的器官分化，对各发育程度种子进行了标准发芽测定及田间幼苗活力鉴定。

Development and Field Vigor of Winter Wheat Seed

The development and differentiation of etiibryoes,and the germination ability and the vigor of wheat seeds collected From various developing stages were studied. Six genotypes of winter wheat were evaluated from 1993 to1994 in Beijing, China Agricultural University. Drv weight of seed was obtained f@oni samples harvested at threeday intervals from 5 to 39 davs after anthesis(DAA). The early developing process of seed embryos (5-14 DAA)of two genotypes were observed. Seed germination ability and vigor were measured beginning at 5 DAA using thestandard germination test and by planting in field respectively.Dry weight of seed increased continually before PM and decreased little after PM (0.4% - 5.4% ). Tlie embryolum, coleoptileancifirst leave were differentiated on 1 1 DAA'S. Furthermore, second leave, first pair of branch embryonic roots and epiblast emerged on 14 DAA's.The germination percentage and the rate of field emergence of 5 DAA seeds were 54% and 39% respectively;The germination ability of 20 DAA seeds and the tilleritig ability of 23 DAA's coincided with that of seeds collectedat PM. Level of seed vigor increased progressively until moisture concentration of seed reaching 12. 3% when was 3-6 days after PM (average over six genotypes). However, the rate of emergence of 14 DAA's seeds (92%) wasalmost Teaching that of the seeds collected at PM (95% ) and the seedlings of 14 DAA could safely pass the coldwinter in Beijing. The data suggest that seed harvested at 14 DAA may be used for breeding programmes or agricultural produtioii. The materials used in this study present difference in germination ability and vigor due to different genotype.