不同染色体倍性甜瓜种子萌发特性研究

Germination characteristics of melon seeds with different ploidy levels

【目的】探讨不同染色体倍性甜瓜种子萌发特性,为多倍体甜瓜的栽培与育种提供理论依据。【方法】以两个二倍体甜瓜品种及其诱导的同源四倍体、三倍体为材料,研究不同染色体倍性甜瓜种子发芽率、发芽指数、活力指数、胚根长、下胚轴长和侧根数变化趋势。【结果】甜瓜二倍体种子发芽率高于三倍体和四倍体,薄皮甜瓜比厚皮甜瓜种子发芽率高;不同倍性甜瓜种子发芽指数、活力指数大小依次为二倍体>三倍体>四倍体,厚皮甜瓜种子的活力指数较薄皮甜瓜高;胚根长、下胚轴长度和侧根数均表现为随着催芽时间的增加而上升、随着倍性的增加而下降的总趋势。【结论】不同染色体倍性甜瓜种子的萌发特性存在差异,甜瓜种子的萌发力并不都是随着倍性的增加而增大,甜瓜二倍体种子萌发力高于三倍体和四倍体种子的萌发力。

【Objective】The germination characteristics of melon seeds with different ploidy levels were studied in order to cultivate polyploid melons and help in breeding programs to develop good melon varieties. 【Method】Two diploid melon cultivars （thick-skinned melon Y2x and thin-skinned melon J2x） including their different ploidy levels （triploid crossed with 4x × 2x and autotetraploid induced with colchicine） were selected for studying their germination rate, germination index, vigor index, radicle length, hypocotyl length and number of lateral roots. 【Result】The germination rate of diploid melon seeds was found to be higher than that of triploid and tetraploid melon seeds and the germination rate of thin-skinned melon seeds was higher than that of thick-skinned melon seeds. The order of germination index and vigor index of melon seeds with different ploidy levels was as follows： diploid triploid tetraploid. The thick-skinned melon showed higher vigor index compared to thin-skinned melon. The radicle and hypocotyl length and number of lateral roots increased with increasing germination time and decreased with increasing ploidy. 【Conclusion】The melon seeds with different ploidy levels differed in seed germination characteristics. The germination activity of melon seeds did not always increased with increasing ploidy levels. Diploid melon seeds showed higher germination percent compared to triploid and tetraploid melon seeds.