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  

YUAN Zhi-you  LI Xian-li  Li Ling-hao  HAN Xing-guo  YAN Tian-li 《中国农业科学(英文版)》2003,2(5)

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   

野蔷薇种子休眠机理研究   总被引：1，自引：0，他引：1  

朱小虎  王晴  程世平 《山东农业科学》2013,(10):59-62

以5种野蔷薇种子为试材，初步分析了影响野蔷薇种子萌发的内在生理因素。结果表明：5种野蔷薇种子大小均匀，种壳占种子风干重的40％～60％，透水性良好；种子浸出液的相对电导率较低，为16％-30％，种子活力较高；种皮脱落酸的含量远高于胚中。  相似文献   

Development of Rice “Seed-Mats” Consisting of Hardened Seeds with a Cover of Soil for the Rice Transplanter     

《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   

Dormancy release in male flowers of <Emphasis Type="Italic">Cryptomeria japonica</Emphasis>     

Taira Hideaki 《Journal of Forest Research》2003,8(3):227-229

To clarify key characteristics of the process whereby dormancy is released in male flowers of Cryptomeria japonica, twigs with male flowers were collected every three days between December 1992 and February 1993. Half of the twigs collected on each date were chilled at 0°C for three days and the cumulative temperatures required by the chilled and non-chilled flowers for florescence were compared. There was no difference in the cumulative temperature required for florescence between chilled and non-chilled male flowers collected before 19 December. However, for samples collected between 21 December and 21 January, the cumulative temperature needed for the florescence of chilled male flowers was 8–68°C lower than that required for non-chilled male flowers. However, there was little difference again in the cumulative temperature required to induce the florescence of chilled and non-chilled male flowers for collection dates later than 24 January. These results suggest that the dormancy of male C. japonica flowers was gradually released by exposure to low temperature and the process was completed by 24 January. The cumulative temperature required for florescence and the sum of the mean daily temperatures between the date of collection and the date of natural pollen dispersal were almost equal after the dormancy of the male flowers was released. The exact day on which pollen will be released can be predicted using the dormancy characteristics of male flowers.  相似文献   

Effects of presowing treatments, desiccation and storage conditions on germination of Strychnos nux-vomica seeds, a valuable medicinal plant     

V. Sivakumar  R. Anandalakshmi  R. R. Warrier  M. Tigabu  P. C. Odén  S. N. Vijayachandran  S. Geetha  B. G. Singh 《New Forests》2006,32(2):121-131

Seeds of Strychnos nux-vomica have slow and erratic germination; thus different presowing treatments were applied to enhance the germination of its seeds collected from Tamaraikulam, Tamil Nadu, India. In addition, the effects of desiccation and different storage conditions on the germination of S. nux-vomica seeds were investigated. The results show that soaking in 500 ppm gibberellic acid (GA₃) for 24 h, incubation of seeds at 40 °C for 3 days and alternate water soaking (16 h) and drying (8 h) for 14 days significantly increased the percentage germination compared to the control. Desiccation of seeds down to 10% moisture content resulted in better germination. Germination of S. nux-vomica seeds differed significantly between different storage periods, moisture contents of the seed and for first and second order interactions (p<0.001). The highest germination (92%) was achieved when seeds with 10% moisture content were stored at ambient temperature for 30 weeks. Evidence from the present study indicates that S. nux-vomica seeds possess physiological dormancy that can be broken effectively by after-ripening. As seeds of S. nux-vomica are found to be desiccation tolerant, dry seed (10% moisture content) can be hermitically stored at ambient temperature for 30 weeks without losing their viability.  相似文献   

Predispersal seed predation in Acacia macrostachya,its impact on seed viability,and germination responses to scarification and dry heat treatments     

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   

单氰胺对设施大樱桃萌芽的促进作用     

孙瑞红  李爱华  李晓军  张玉涛  刘建伟 《中国农学通报》2007,23(7):412-412

为了探讨单氰胺对大樱桃萌芽和成熟期的影响，萌芽前，在平度、泰安两地的“红灯”樱桃树上喷洒单氰胺1.5%和2.5%溶液。平度保护地的施药时间为2003年12月24日，泰安保护地和露地的施药时间分别为2004年1月12日和2月10日。试验结果表明，单氰胺能有效促进大樱桃萌芽和开花。平度试验点：经单氰胺处理的樱桃萌芽、开花、成熟期分别比对照提前13d、8d、7d，单果重略小于对照。泰安试验点：经单氰胺处理的萌芽期比对照提前7d，但果实成熟期与对照差异不明显。因此，单氰胺在大樱桃上的作用效果与施药时期有关  相似文献   

马铃薯块茎休眠及萌发过程中几种酶活性变化   总被引：10，自引：1，他引：10  

王鹏  连勇  金黎平 《华北农学报》2003,18(1):33-36

以马铃薯脱毒试管薯为试验材料，研究块茎休眠和块茎顶芽萌发生长过程中几种相关酶活性变化。结果表明，块茎贮藏过程中淀粉酶、淀粉磷酸化酶、过氧化物酶和多酚氧化酶活性的消长，与块茎形态上的休眠及萌发有密切关系。处于休眠期间的块茎内淀粉酶和淀粉磷酸化酶活性很低，随着休眠的解除及顶芽萌动活性逐渐增强，当顶芽开始生长时活性再镒降低；过氧化物酶和多酚氧化酶在块茎休眠时活性较高，顶芽萌动后活性迅速下降；不同品种间这四种酶的变化趋势基本相同。  相似文献   

茄砧托鲁巴姆(Solanum Torvum)种子休眠与萌发习性研究   总被引：5，自引：0，他引：5  

林桂荣  周宝利 《种子》2005,24(5):36-38

本文以西安绿茄为对照,对野生茄砧托鲁巴姆种子的休眠与萌发习性进行了系统研究.结果表明,托鲁巴姆种子小、含水量低、吸水速度慢,室温下需浸种48～72h种子才能饱和.种子催芽期淀粉酶的含量和活性的变化与萌芽生长密切相关,托鲁巴姆催芽期淀粉酶的含量和活性都明显低于西安绿茄,可能是托鲁巴姆种子发芽困难、发芽速度缓慢的原因之一.托鲁巴姆种子脱落酸含量高,玉米素、赤霉素和生长素的含量低,是种子发芽困难、发芽时间长的主要原因.在种子浸种催芽过程中,采用适宜的外源生长素类物质处理可能打破种子的休眠,促进萌发生长.  相似文献   

枣若干品种需冷量测定   总被引：8，自引：0，他引：8  

贺润平  杜俊杰  赵飞  李捷  牛荣山 《果树学报》2004,21(2):182-184

对枣不同品种冬季休眠的阶段性、需冷量进行了测定,结果表明:枣不同品种度过自然休眠的低温需求量不同。从12月10日到翌年1月20日自然休眠结束,之后进入被迫休眠期。主栽品种中梨枣于12月上旬,金丝小枣于1月中旬结束自然休眠。根据≤7.2℃模型、0～7.2℃模型、犹它模型测定枣的低温需求量。供试品种的低温需求量以平均值计算,≤7.2℃模型、0～7.2℃模型与犹它模型分别为1066h、440h和442CU。把犹它模型作为晋中地区枣品种需冷量的低温标准较为合适。供试的24个枣品种的需冷量为399～580CU。  相似文献