燕山红栗种子休眠与种胚形态、种皮及内含物的关系

Relation between Seed Dormancy and Embryo Form,Testa and Inclusion of Castanea mollissima cv.'Yanshanhong'

以燕山红栗为试验材料,从种胚形态、种皮障碍、内含物变化等多方面,探讨板栗种子休眠的原因.结果表明:种胚发育不成熟是板栗种子休眠的主要原因,随着沙藏时间的延长,板栗种胚长度逐渐增长,子叶与胚轴和胚根长度的比值也逐渐增大;种皮对板栗种子萌发有一定机械束缚作用,去皮程度越高,板栗种子的发芽率也越高;沙藏过程中,种皮中P-香豆酸的含量明显减少,因此认为P-香豆酸可能是抑制板栗种子萌发的另一个原因,而种仁中GA3/ABA比值的变化与板栗种子萌发没有明显的相关性.在此基础上用不同浓度P-香豆酸对板栗种子进行处理,证明P-香豆酸对板栗种子存在抑制作用.

Mechanism of Castanea mollissima cv. ‘ Yanshanhong＇ seed dormancy was studied by exploring the testa effect, embryo form and inclusion variation. The following conclusions were drawn as： The immaturity of embryo should be the major factor to cause＇ the seed dormancy. Both the embryo length and the length ratio of cotyledon and the radicle increased along with prolonging the sand stratification duration. The testa constrained the seed germination to a certain degree, for the germination percentage increased when the seeds were peeled off partially or completely. It was deduced from the experiment that P -coumaric acid could be another factor to inhibit the seed germination, since its concentration dropped obviously along the course of sand stratification. There was no clear relationship between the GA3/ABA ratio in the seed kernel and the germination. The inhibiting effect of P - Coumaric acid was proven by treating Castanea mollissima cv. ＇ Yanshanhong＇ seeds with P-;coumaric acid with varied concentrations.