采用差示扫描量热法研究不同温度及储藏时间下小麦淀粉不同组分(小麦总淀粉、小麦A淀粉、小麦B淀粉)的老化动力学及最大冷冻浓缩状态下玻璃化转变温度(glass transition temperature of the maximally freezeconcentrated state,T_g’)...采用差示扫描量热法研究不同温度及储藏时间下小麦淀粉不同组分(小麦总淀粉、小麦A淀粉、小麦B淀粉)的老化动力学及最大冷冻浓缩状态下玻璃化转变温度(glass transition temperature of the maximally freezeconcentrated state,T_g’)。测定小麦淀粉各组分于-18、-5、4、22℃储藏3~21 d的老化度、T_g’及非冻结水含量。结果表明,不同淀粉组分在-18℃下储藏未发生老化,而在-5、4、22℃条件下储藏会发生老化,且4℃时的老化度最大,22℃时的老化度最小,-5℃时的老化度居两者之间;小麦B淀粉的T_g’比A淀粉的T_g’高。小麦淀粉不同组分老化动力学存在差异,小麦A淀粉的老化度较总淀粉及B淀粉大;非冻结水的含量对不同组分小麦淀粉T_g’有很大影响。展开更多
The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko),exists with holocyclic life cycle in Tacheng, Xinjiang in Northwest China. It produces males and oviparae to mate and oviposit for overwintering by eggs. Unde...The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko),exists with holocyclic life cycle in Tacheng, Xinjiang in Northwest China. It produces males and oviparae to mate and oviposit for overwintering by eggs. Under laboratory conditions with 14 h/d photophase and temperature not lower than 15℃, RWA occurred in parthenogenesis and produced no males. The laboratory popu-lations of Russian wheat aphid, which were kept under natural conditions in fall by 15th, 49th and 81st generation while wild populations produced males and oviparae for mating, produced males and oviparae with their number decreased gradually, but viviparae and nymphs increased sequen-tially. As a result, it produced a small amount of oviparae and no males emerged in fields by 49 generations' reproduction in laboratory. After development of 81 generations, oviparae happened occasionally and no eggs occurred for overwintering instead of viviparae and nymphs. A hypothesis of RWA disastrous process was proposed. The life cycle of RWA can be changed from holocycly to anholocycly in its long-term spread and evolution. Anholocycly is more dangerous than holocycly to small grains for its strong adaptability and dispersal ability.展开更多
文摘采用差示扫描量热法研究不同温度及储藏时间下小麦淀粉不同组分(小麦总淀粉、小麦A淀粉、小麦B淀粉)的老化动力学及最大冷冻浓缩状态下玻璃化转变温度(glass transition temperature of the maximally freezeconcentrated state,T_g’)。测定小麦淀粉各组分于-18、-5、4、22℃储藏3~21 d的老化度、T_g’及非冻结水含量。结果表明,不同淀粉组分在-18℃下储藏未发生老化,而在-5、4、22℃条件下储藏会发生老化,且4℃时的老化度最大,22℃时的老化度最小,-5℃时的老化度居两者之间;小麦B淀粉的T_g’比A淀粉的T_g’高。小麦淀粉不同组分老化动力学存在差异,小麦A淀粉的老化度较总淀粉及B淀粉大;非冻结水的含量对不同组分小麦淀粉T_g’有很大影响。
基金the National Natural Science Foundation of China (Grant No. 39670109) and CAS Special Support Program.
文摘The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko),exists with holocyclic life cycle in Tacheng, Xinjiang in Northwest China. It produces males and oviparae to mate and oviposit for overwintering by eggs. Under laboratory conditions with 14 h/d photophase and temperature not lower than 15℃, RWA occurred in parthenogenesis and produced no males. The laboratory popu-lations of Russian wheat aphid, which were kept under natural conditions in fall by 15th, 49th and 81st generation while wild populations produced males and oviparae for mating, produced males and oviparae with their number decreased gradually, but viviparae and nymphs increased sequen-tially. As a result, it produced a small amount of oviparae and no males emerged in fields by 49 generations' reproduction in laboratory. After development of 81 generations, oviparae happened occasionally and no eggs occurred for overwintering instead of viviparae and nymphs. A hypothesis of RWA disastrous process was proposed. The life cycle of RWA can be changed from holocycly to anholocycly in its long-term spread and evolution. Anholocycly is more dangerous than holocycly to small grains for its strong adaptability and dispersal ability.
