自交衰退

产量的自交衰退明显，而荚/株、粒/株衰退幅度较小。

Inbreeding depression in yield was obvious , while that of pods / plant and seeds / plant not too large .

因为自交产生的后代较差（自交衰退），因而很难与后作用SI系统区分开来。

The production of weak offspring as a result of selfing , inbreeding depression , may be hard to distinguish from late-acting SI systems .

种子场圃发芽率及苗高的自交衰退非常严重。直干桉自交衰退非常严重，有8个组合的数量性状显著高于平均值。

High selfing depression occurred in the germination percentage and in the seedling height . Eight combinations were dominant on quantitative characters .

居群隔离、自交衰退可能是导致云锦杜鹃居群间遗传分化的主要原因。

These results suggested that population isolation and inbreeding regression may play the main roles in the genetic differentiation among Rhododendron fortunei populations .

结果表明南方白菜型油菜自交严重衰退、连续自交四代，其主要农艺性状与开放授粉或与姐妹系间的后代差异达显著或极显著水平。

Results indicated that the depression of inbreeding in B.chinensis was very serious , the agronomic traits and yield in bud pollination lines were lower than that in spontaneous pollination and crosses between sister lines with significant or very significant level .

对杂交一代西瓜亲本进行严格的选择，不仅能够延缓自交亲本的衰退，改善或提高其生长势、座果性、抗病性和产量等性状，而且可以防止杂交一代的退化。

The strick parent selection of hybrid watermelon breeding not only delayed the depression of self bred parent , improved or strengthened the ability of its growth , fruit setting and resistance , but also controlled the degeneration of hybrid watermelon combination .

杉木具有较高的自交率，但衰退是普遍的，在良种繁育及长期育种中应予注意避免或利用；

Chinese Fir has considerable self-crossing rate but its failing effect is common , which we should pay attention to avoid or apply in the practice of breeding good strains and in the study on long term breeding ;