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51.
Effects of Temperature and Several Chemicals on Metabolic Changes During Dormancy Release in NJ72 Nectarine 总被引:1,自引:0,他引:1
Poor, delayed and ununiform budbreak is a major problem for peaches in greenhouse. To clari-fy the mechanism of breaking bud dormancy in nectarines, the effect of temperature and three dormancy-breaking agents on metabolic changes during dormancy release in two-year old NJ72 nectarine (Prunus persicaL. Batch) was investigated. The result showed temperature and chemicals affected the budbreak and the me-tabolism of NJ72 nectarine during dormancy. Endogeneons peroxide content in buds increased soon after lowtemperature treatment. Meanwhile, catalase activity was also shown to increase significantly at low temperature treatment, coincided with increase of the activity of peroxidase and superoxide dismntase. The rate of res-piration in flower buds increased at low temperature during dormancy. The rate of the pentose phosphate path-way increased, while the rate of the Embden-Meyerhof pathway decreased and the rate of triearboxlic acid cycle changed little. Glucose 6-phosphate dehydrogenase activity increased at low temperature during dormancy.At the same time we found an accumulation of peroxide after treatment with dormancy-breaking chemicals. Inflower buds treated with dormancy-breaking agents, thiourca, KNO3 and NH4 NO3, catalase activity was in-hibited soon after treatment, whereas peroxidase activity increased, and the changes of superoxide dismutaseremained little. In this study, it was found that the rates of respiration in flower buds increased by chemicalssprays during dormancy. The activity of glucose 6-phosphate dehydrogenase, the key enzyme in the pentosephosphate pathway (PPP), increased by spraying with dormancy-breaking agents, concomitantly with the ac-tivatlon of the pentose phosphate pathway. 相似文献
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低温解除休眠过程中兰州百合中部鳞片物质变化的生理机制 总被引:18,自引:0,他引:18
以兰州百合为试材,研究了2℃、6℃、10℃条件下保湿贮藏101 d内兰州百合中部鳞片中碳水化合物、酚类物质、游离氨基酸以及内源激素的变化对解除休眠的影响。结果表明,随着处理温度降低和处理时间延长,淀粉明显降解、ABA含量显著下降,可溶性糖、酚类物质、内源GA3、IAA含量急剧增加。低温处理初期的34 d是上述物质变化最活跃的时期。相关分析表明,淀粉酶和PAL活性升高是分别导致可溶性糖和酚类物质含量增加的因素。低温贮藏期间,游离氨基酸总量呈下降趋势,其中精氨酸含量最高、变化最大。根据逐步回归分析和通径分析的结果初步判定鳞片内碳水化合物、酚类物质和游离氨基酸等物质变化主要受内源GA3的调控。 相似文献
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Schelin Maria Tigabu Mulualem Eriksson Ingalill Sawadogo Louis Christer Odén Per 《New Forests》2004,27(3):251-267
Predispersal seed predation among individual Acacia macrostachya trees over two sites in Burkina Faso was assessed. In addition, the effects of seed predation on seed viability; germination responses to scarification (mechanical, hot water at 60, 70 and 80°C, and sulphuric acid for 10, 20 and 30 min) and dry heat (at 60, 70 and 80°C for 15, 30 and 60 min each) treatments were investigated under laboratory conditions. The results indicated a large difference in predation intensity among individual trees, as well as between sites. Predispersal predation significantly decreased seed germination, particularly when the number of insect larvae per seed increased. Scarified and unscarified seeds germinated equally well, except for hot water treatments of high temperature. This indicates lack of physical dormancy and dispersed seeds can readily germinate provided that conditions for germination are conducive. Seeds exposed to dry heat treatments also germinated close to 97% under low intensity and short exposure times. This suggests that fire, under natural condition, plays a key role in triggering germination of A. macrostachya seeds. 相似文献
56.
《Plant Production Science》2013,16(1):108-115
Conventional seedling mats for rice transplanters in Japan are heavy to carry, and much labor is required to collect, wash and store the nursery boxes. In addition, seeding time overlaps with the labor peak in spring. To reduce such labor, we developed a “seed-mat” consisting of hardened rice seeds (Oryza sativa L.) glued onto a molded rice-hull mat with a cover of soil glued on. Seed hardening, which is done by soaking seeds in water at 15ºC for 5 d followed by drying, and heating of the seeds at 50ºC for 5 or 7 d, reduced the time to 50% germination (T50). In dormant seeds, the heating before the hardening enhanced the effect of the hardening more than the heating after the hardening. Seed hardening increased the dry weight of the shoots from the seed-mats. Covering the mat with soil also increased the percentage of seedling emergence, shoot length, number of leaves and shoot dry weight of the seed-mats. The hardened seeds maintained short T50 and 95% or higher germination for 120 d at room temperature. In the seed-mat, the hardened seeds maintained 95% or higher seedling emergence for 208 d. In conclusion, superior seed-mats could be produced using the procedure involving both seed hardening and cover of soil. The seed-mats can be prepared in winter and stored until seedling-raising period in spring. By the seed-mats, seedling mats can be prepared for the rice transplanter without using nursery boxes, which take up storage space and require much labor. 相似文献
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温度对甜樱桃花芽酚类物质含量和相关酶活性及休眠的影响 总被引:5,自引:3,他引:5
以7年生甜樱桃红灯(PrunusaviumL.cv.Hongdeng)带有花芽的离体枝条为试材,研究了不同温度对红灯花芽酚类物质含量、相关酶活性及萌芽率的影响。结果表明,不同温度处理对酚类物质含量影响效果不同,自然休眠前期低温(5℃)减缓了酚类物质的积累,中期提前达到其高峰并进入下降阶段,后期加速其降低;高温(20℃)则效果相反,变温(5℃/20℃)的效果不明显。自然休眠的不同时期,不同的温度处理对PAL和PPO活性的影响效果也不相同,低温(5℃)在休眠前期抑制PAL活性的增长而提高了PPO活性,中期使PAL活性迅速降低的同时却加速了PPO活性的升高;后期降低了PAL活性,提高了PPO活性。高温(20℃)的作用效果与低温(5℃)相反。变温(5℃/20℃)对PAL和PPO活性的影响效果不明显。低温(5℃)在自然休眠的3个阶段都能打破休眠促进萌发;高温(20℃)抑制了花芽的萌发;变温(5℃/20℃)对花芽的萌发影响不大。 相似文献
60.
东方百合鳞茎长期冷藏期间形态和生理变化研究 总被引:5,自引:0,他引:5
以浙江省山地自繁的东方百合鳞茎'索蚌'(Sorbonne)为试材,探讨了5℃冷藏条件下鳞茎的芽伸长变化,以及贮藏性和代谢性养分的变化规律.结果表明:百合鳞茎内的新芽在冷藏过程中不断伸长,60 d后顶芽生长点距鳞茎端部的距离小于1 cm,继续冷藏1个月后新芽突破顶端.在贮藏的前2个月,淀粉含量明显下降,外层鳞片是3层中下降幅度最大的,后2个月淀粉含量趋于缓慢上升.可溶性总糖和蔗糖含量在贮藏的5个月时间里,均呈不断上升的趋势.中层鳞片的可溶性总糖含量增幅最大,达到了196.11%. 相似文献