不同药剂对破除播娘蒿种子休眠的效应

播娘蒿种子休眠的自动存作约需半年时间。研究了不同药剂对破除其休眠的效应。结果表明：药剂浸种可迅速打破其种子休眠,其中以３０％浸种３０ｍｉｎ,作用最显著,破眠率可达９３％,其次是３００×１０＾６ＧＡ浸种２４ｈ,ＮａＯＨ,ＰＥＧ,ＰＶＡ等作用较弱。     

喜树的种子休眠及更新

对喜树种子的休眠与更新进行了研究．结果表明,喜树种子成熟后有约４个月的休眠期．种子内部生物钟节律与所处环境的气候年变化节律相似,使种子处于周期性休眠状态．喜树种子的天然寿命约２年．大树和中树种子的天然更新能力优于小树和枯梢树．天然环境通过抑制已萌发种子的成苗和幼苗的生长发育而限制喜树利用种子进行自然更新,适当的人为干扰可大大促进自然更新．     

Optimal life strategies in organisms exposed to recurrent critical events

The optimal partition of energy between survival and reproduction is considered for a population subject to recurrent and potentially lethal critical events. The best strategy is found by maximizing fitness, a functional derived from the Lotka equation. The dynamics is governed by a second-order, age-varying, nonlinear system. The energy storage and the probability of survival are the state variables, while the amounts of energy placed into and withdrawn from the storage are the controls. The optimal life strategy is shown to be as follows: build up the storage at the very beginning of life, and then progressively deplete it to resist the critical events.This work was partially supported by MURST Project Ricerche sui Fondamenti della Conservazione della Natura. The authors would like to thank C. Ricci for suggesting the problem and C. Matessi for helpful discussion.     

钟萼木种子贮藏与休眠解除技术的研究

通过对新采集的钟萼木种子进行各种处理后进行发芽试验,结果表明,钟萼木种胚、内种皮及胚乳内均含抑制物质且可引起种子休眠,但引起种子休眠的主要原因是种子内缺乏萌发促进物质和酶活性低所致。用ABT生根粉溶液浸种24h或低温(5℃)层积60d,可解除种子休眠,萌发率由28%可提高到80—90%。低温层积后适宜的萌发温度为30℃、25℃和20℃,其次是变量条件(昼30℃,夜20℃),将种子置于聚乙烯薄膜袋内低温(5℃)干藏85d,也可解除休眠,低温干藏85d后再层积20d,解除休眠的效果最佳,如此处理置床后第5d即开始发芽,15d完成萌发过程,萌发率达85%。     

山楂种子休眠与萌发生理研究 Ⅳ.山楂种子内果皮及种皮与种子休眠的关系

通过对１９９４年和１９９５年采收的山楂种子进行层积、发芽、组织培养、生活力测定、ＧＡ３处理等多种方法进行研究认为，层积中山楂种子先解除休眠而后破壳；种子子叶休眠时间短，并可在干藏条件下解除休眠，休眠解除后，种皮抑制其生长；在种子发育过程中，子叶进入休眠前，种皮对子叶生长有一定作用；干藏７个月以内的种子，去除种皮或去除种皮及子叶，胚芽、胚轴、胚根不能萌发     

赤霉素对'大富贵'芍药休眠解除及内源激素和糖类代谢的影响

研究不同质量浓度赤霉素（GA₃，0、100、200、300、1 000 mg/L）替代低温解除芍药品种‘大富贵’休眠的效果，探讨休眠解除前后其内源激素和糖类代谢生理变化，为生产上利用GA₃解除芍药休眠及调控花期提供理论及技术支撑。     

Hopf-zero bifurcation of a delayed predator-prey model with dormancy of predators

In this paper, We investigate Hopf-zero bifurcation with codimension 2 in a delayed predator-prey model with dormancy of predators. First we prove the specific existence condition of the coexistence equilibrium. Then we take the mortality rate and time delay as two bifurcation parameters to find the occurrence condition of Hopf-zero bifurcation in this model. Furthermore, using the Faria and Magalhases normal form method and the center manifold theory, we obtain the third order degenerate normal form with two original parameters. Finally, through theoretical analysis and numerical simulations, we give a bifurcation set and a phase diagram to show the specific relations between the normal form and the original system, and explain the coexistence phenomena of several locally stable states, such as the coexistence of multi-periodic orbits, as well as the coexistence of a locally stable equilibrium and a locally stable periodic orbit.     

提高杨梅种子出苗率的研究

杨梅种子发芽出苗率代,是培育杨梅嫁接砧木材料的一大难题。本试验采用了不同采种期、不同品种以及打破种子休眠等措施进行了提高其出苗率的研究。结果表明：杨梅果实成熟时采种,采用层积或秋播,种子出苗率较高。种子层积后播种前硒裂,并用5000倍翠竹牌植物生长调节剂处理种子,可使种子出苗率提高到91．1％。