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1.
宁夏梨树霜冻指标试验研究 总被引：4，自引：1，他引：3
霜冻是制约着梨树生产的主要农业气象灾害之一,探究梨树霜冻指标可为梨树霜冻预报、监测预警及梨树霜冻灾害风险评估和灾害防御提供参考。笔者采用人工霜箱开展模拟霜冻试验对梨树开花期及幼果期遭受霜冻的临界温度及持续时间进行研究,结果表明：-4℃是梨花器官遭受霜冻的致死温度,‘玛瑙’梨花期遇-3℃低温持续2 h 遭受轻度霜冻,持续2.5 h 遭受中度霜冻;重度受冻的临界温度及持续时间为-3℃持续3 h 及以上、-3.5℃持续时间大于等于0.5 h 或-4℃及以下。‘甘泉’和‘新高’的耐冻性差于‘玛瑙’。对于幼果,3 个品种的耐冻性差异不大,-2℃持续2~3 h 或-2.5℃持续1 h 幼果出现轻度受冻;-2.5℃持续2~3 h,-3℃持续1 h 为中度受冻,-2.5~-2℃持续4 h、-3℃持续1 h 以上为重度受冻。未达到致死温度时,随着持续时间延长,受冻程度增加,幼果直径越小,受冻越严重。 相似文献
2.
宁夏杏、李子花期幼果期霜冻指标试验研究 总被引：1，自引：0，他引：1
霜冻是制约宁夏经济林果生产的主要农业气象灾害之一,探究不同果树霜冻指标可为果树霜冻预报、监测预警及果树霜冻灾害风险评估和灾害防御提供参考。本研究采用人工霜冻模拟箱模拟霜冻试验,对杏树、李子树开花期及幼果期遭受霜冻的临界温度及持续时间开展研究,结果表明：2个杏品种‘金太阳’和‘李梅杏’花期遭受霜冻的温度指标差异不大,-2℃为轻度受冻,-2~-3℃之间为中度受冻,＜-3℃持续时间大于1 h则为重度受冻。4个李子品种花期‘尤萨’的耐冻性较强,在-3℃下持续4 h仅轻微受冻,其他品种在-3℃下就会严重受冻,‘龙园秋李’的耐冻性最差,-3℃持续1 h受冻率就会达到50%。杏幼果在-2.5℃持续1~2 h为轻度受冻,3~4 h为中度受冻,小于或等于-3℃持续1 h及以上为重度受冻,2个品种差异不大。李子幼果的耐冻性差于杏幼果,‘尤萨’在-1℃持续3~4 h和-2.5℃持续1 h就会轻度受冻,-2℃和-2.5℃时持续时间大于等于2 h或者遇-3℃低温就会重度受冻。‘兰蜜李’-2℃和-2.5℃大于或等于3 h或者温度小于等于-3℃为重度受冻。 相似文献
3.
4.
广西油茶主栽无性系低温半致死温度与耐寒性研究 总被引：2，自引：1，他引：1
为了鉴定广西主栽无性系的耐寒性,采用电导法测定广西主栽的4个油茶无性系‘岑软2号’、‘岑软3号’、‘岑软22号’和‘岑软24号’在不同低温下细胞膜透性的变化,配合Logistic方程,分别求出低温半致死温度(LT50)。结果表明：随着温度的降低,细胞伤害率呈“S”型曲线变化,与温度呈极显著负相关;4个无性系的低温半致死温度分别为-9.0℃、-12.6℃、-9.9℃、-10.8℃,耐寒性由强到弱依次为：‘岑软3号’＞‘岑软24号’＞‘岑软22号’＞‘岑软2号’。 相似文献
5.
基于果园实测气温的库尔勒香梨树越冬冻害成因分析 总被引：2，自引：1，他引：2
探讨香梨园越冬冻害发生的气温要素,为库尔勒香梨种植的气象决策服务提供参考。通过近4年对库尔勒地区上户镇果园的香梨树越冬休眠期间冻害调查和温度监测,对极端低温、低温持续时间等指标进行统计分析,结果表明：2010—2011年度,该地的香梨树发生了中等强度的越冬休眠期冻害,果园实测的极端低温达到-28.1℃,极端低温日（1月10日）-24℃以下低温的持续时间达到9.5 h。2011—2012年冬季,果园实测极端低温为-26.3℃,但极端低温日-24℃以下低温的持续时间仅为3.0 h,未能造成香梨树明显冻害。分析近4年库尔勒地区上户镇的香梨冻害情况,冬季无或仅微量降雪,果园低温强度大、出现频率高易引发果树冻害,果园实测气温低于香梨树冻害临界温度时未必会发生冻害,关键在于果园出现冻害天气时冻害温度的持续时长,而持续时长以冻害温度连续出现的天数计量并不可靠。此外,低温在冬季出现的时期也对香梨树冻害程度产生影响。 相似文献
6.
延安5次苹果花期冻害影响分析 总被引：2，自引：0，他引：2
《中国农学通报》2018,(32)
为提升苹果花期冻害气象预警和灾害防御水平,笔者利用2001年以来延安出现的5次苹果花期冻害天气过程,通过对比分析温度、花朵受冻率和产量。结果表明:延安市苹果花期冻害有日期提前和影响加重的趋势;严重冻害年具有温度通过0℃初日早、3月温度明显偏高、积温高的特征;不同物候期形成冻害指标不一样,整个花序受冻指标在中心花开放期和花序分离期,过程极端最低气温在-3℃左右时,少量中心花受冻,最低气温≤-4℃会形成轻度受冻,最低气温≤-5℃出现中度受冻。盛花期当温度降至-3℃时出现轻度受冻;-4℃时出现中度受冻;-5℃以下时重度受冻。今后花期冻害天气的预报及影响评估,既要考虑冻害过程最低温度值,也要重点考虑通过0℃初日、3月温度与活动积温情况,前期气温是否异常偏高等现象。 相似文献
7.
《中国农学通报》2020,(1)
为减少莲雾寒冻害损失,亟需建立不同品种莲雾果苗寒冻害等级指标。根据大尺度灾情数据记录3种莲雾果苗样本形态,对照形态学标准确定寒冻害等级,结合数理统计和对比方法建立指标。结果确定了3种莲雾果苗寒冻害等级指标。‘大叶’:T_m4.5℃,无寒冻害;1.5℃T_m≤4.5℃,轻度;-1.0℃T_m≤1.5℃,中度;-3.0℃T_m≤-1.0℃,重度;T_m≤-3.0℃,极重。‘黑珍珠’:T_m5.5℃,无寒冻害;3.0℃T_m≤5.5℃,轻度;0.5℃T_m≤3.0℃,中度;-2.5℃T_m≤0.5℃,重度;T_m≤-2.5℃,极重。‘紫红’:T_m5.5℃,无寒冻害;2.0℃T_m≤5.5℃,轻度;0℃T_m≤2.0℃,中度;-1.5℃T_m≤0℃,重度;T_m≤-1.5℃,极重。建立的指标通过低温箱试验、地理移置试验和历史灾情样本验证,具有实用意义。 相似文献
8.
海水养殖与气象Ⅰ——石斑鱼低温寒害指标试验研究 总被引：1，自引：1，他引：0
本研究可揭示不同大小石斑鱼抗寒性差异及其机体应激反应,探索斜带石斑鱼生存的临界温度,为石斑鱼养殖选择合理放养周期、寒害风险评估、制定防寒减灾决策提供科学依据。试验以5、200、600 g/尾斜带石斑鱼为研究对象,通过逐渐降低水温并记录不同水温下的存活情况,并测定其超氧化物歧化酶含量。结果表明：（1）石斑鱼小鱼轻度寒害指标为水温11℃,持续1天,中度寒害指标为水温10℃,持续时间1~2天,重度寒害指标为10℃,持续3天。中鱼的轻度寒害指标为14℃,持续1天,中度寒害指标12℃,持续1天,重度寒害指标为11℃,持续1天。大鱼的轻度寒害指标为15℃,持续1~2天,中度的寒害指标为15℃,持续3天,重度寒害指标为14℃,持续1天;（2）小石斑鱼在低温刺激下,肝和鳃SOD显著提高,中鱼鳃SOD显著下降,而肝SOD先升高后下降,大鱼肝SOD和鳃SOD都先升后降,但整体活性水平相对稳定。 相似文献
9.
河套灌区籽用葫芦终霜冻指标研究 总被引：1，自引：1，他引：0
为了完善当地气象灾害指标,更好地开展籽用葫芦春霜冻气象服务,本研究选用籽用葫芦‘(丰产一号)’幼苗为试验材料,利用MSX-2F人工模拟霜箱系统模拟自然降温过程,通过测定幼苗的叶温记录植株冻伤、冻死情况,结合荧光参数值,综合确定河套灌区籽用葫芦终霜冻指标。结果表明：(1)籽用葫芦幼苗全部冻死的最低温度为≤-4℃;(2)籽用葫芦幼苗结冰点的范围为-0.2~-2.8℃之间,过冷却点的范围为-1.5~-4.5℃之间;(3)苗龄越大的籽用葫芦幼苗,耐受冻害的能力越强;(4)籽用葫芦幼苗轻霜冻地表温度指标为-1℃,重霜冻地表温度指标为-3℃。 相似文献
10.
枇杷幼果雨雪冻害的理化响应 总被引：1，自引：1，他引：0
为了探究-3℃~0℃区间枇杷幼果受冻原因,雨雪天气后采集套袋处理或树冠是否覆膜保护的未受冻和受冻果实,检查其受冻情况和检测其游离脯氨酸等理化指标。结果表明:树冠覆膜保护的果实未受冻,树冠未覆膜的果实、经过雨雪淋洗后受冻;果实套袋处理,悬空于袋内的果实未受冻、与袋子贴近的果实受到冻害;受冻果实的游离脯氨酸含量显著高于未受冻果实;套袋受冻果实的丙二醛含量显著高于未受冻果实,而覆膜和未覆膜果实的丙二醛含量无显著差异;SOD、POD、PPO的活性在未覆膜果实和覆膜果实之间差异显著,未覆膜果实中三者的活性较高,然而这3种酶的活性在套袋果中活性较低,套袋受冻果实和未受冻果实之间无显著差异。本研究表明,不同形态(气液固)的低温传导介质,是导致枇杷幼果在-3℃~0℃区间是否受冻的主要原因,液固态低温传导介质才会导致枇杷幼果受冻,游离脯氨酸含量或许是鉴别枇杷果实是否受冻的关键理化指标。 相似文献
11.
Jens Jensen 《Euphytica》1979,28(1):47-56
Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans. 相似文献
12.
Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts 总被引：7，自引：0，他引：7
Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed. 相似文献
13.
Hongyan WEI Jian ZHOU Jinguang LU Jingzheng SONG Qiongxi YU Zhihong JIANG 《Medicinal Plant》2019,(6):27-29
[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol... 相似文献
14.
C. J. Spurr D. A. Fulton P. H. Brown R. J. Clark 《Journal of Agronomy and Crop Science》2002,188(4):275-280
Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality. 相似文献
15.
Chunli TANG Fengxian ZHAO Hongxia CHEN Jiabao MA Jiangcun WEI Meiyan QIU Zhen XIE 《Medicinal Plant》2019,(6):60-65
[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination... 相似文献
16.
D. A. Bond G. J. Jellis G. G. Rowland J. Le Guen L. D. Robertson S. A. Khalil L. Li-Juan 《Euphytica》1993,73(1-2):151-166
Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses. 相似文献
17.
Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed. 相似文献
18.
[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho... 相似文献
19.
E. Keep 《Euphytica》1986,35(3):843-855
Summary Cytoplasmic male sterility (cms) is described in the F1 hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf
1) and recessive for the other (Rf
2).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph
3(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf
1(one of two dominant additive genes controlling early season leafing out) indicated that Rf
1and Rf
2were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf
1, and 0.15 for Lf
1-Sph
3were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph
3.It is suggested that competitive disadvantage of lf
1-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph
3. Poor performance of lf
1- (and possibly lf
2-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off). 相似文献
20.
Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques. 相似文献