镉胁迫对不同地区亚麻主栽品种种子萌发的影响

为了明确不同品种亚麻种子对镉胁迫反应的差异,2014年以来自不同地区的10个纤用和油用亚麻主栽品种为材料,研究了不同程度镉胁迫对种子萌发的相对发芽势、相对发芽率、相对芽长、发芽指数和活力指数的影响,并对供试品种耐镉性进行了综合评价。结果表明,500μM以下的镉胁迫对亚麻种子发芽的影响较小,且对部分亚麻品种的发芽有促进作用;500μM以上随着镉浓度的升高,10个亚麻品种的种子萌发性能均有不同程度的下降;芽长受镉胁迫的影响较发芽势和发芽率更大。耐镉性综合评价表明晋亚9号对镉胁迫的耐性最强,派克斯耐性最弱。本研究可为亚麻品种耐镉性筛选和耐镉育种提供理论参考,筛选出的强耐镉性亚麻品种可作为不同地区镉污染农田的候选替代种植作物。     

镉胁迫对不同品种辣椒种子萌发及苗期抗性生理的影响

辣椒(Capsicum annuum L.)不仅是重要的蔬菜和调味品,也是贵州的主导产业之一,但耕地镉(Cd)污染严重制约了辣椒产业的发展.本研究以前期筛选的耐镉辣椒品种LCL 4和LCL 6为材料,研究CdCl2胁迫对两品种种子萌发及理化指标的影响.结果表明,在200 mg·L-1 CdCl2胁迫条件下,LCL 4和...     

吡虫啉拌种对不同小麦品种萌发的影响

为评价吡虫啉拌种荆对四川主栽小麦品种的安全性,选择了10个代表性品种,拌种后测试发芽率、发芽势、发芽指数、胚芽长、最长根长等参数.结果表明,各参数均存在显著的拌种、品种以及互作效应.拌种后的发芽率、发芽势和发芽指数均呈下降趋势,平均降幅分别为1.7％、2.9％和8.2％,不同品种反应差异明显.川麦42、川麦38等品种发芽率、发芽势未受影响,发芽指数降幅也较小(3％左右),而川农16、蜀麦969拌种后发芽率、发芽势和发芽指数均有大幅降低.拌种对胚根和胚芽生长也有明显抑制作用,胚芽长平均降低50.1％,最长根长平均降低73.0％,其中川农16、绵麦37、川麦61等品种2个参数降幅较大,川麦38的降幅相对较小.以上结果说明,不同类型品种对吡虫啉拌种剂的敏感程度不同,川农16、蜀麦969较敏感,川麦38、川麦42不敏感,其他品种介于两类品种之间.     

镉对紫花苜蓿种子萌发的影响

研究了重金属Cd对紫花苜蓿种子萌发及幼苗生长的影响,结果表明,0.00~15mg/kgCd具有提高种子发芽率、发芽势、活力指数及促进芽生长的作用,高浓度的Cd则降低种子的发芽率和活力指数。Cd对紫花苜蓿根的抑制效应大于芽。     

不同外源物质对31号柴胡种子萌发的影响

采用KMnO_4、GA_3、Ca Cl_2、Mg SO_4和6-BA对31号柴胡种子进行浸种处理。结果表明GA3对柴胡种子萌发具有明显的促进作用,当其浓度为250mg/L时促进作用最为明显,可大大提高柴胡种子发芽率和发芽势。当6-BA浓度为0.5mg/L时,对柴胡种子也具有明显的促进作用。而低浓度的Mg SO4、4mg/L的KMnO_4、1mg/L的Ca Cl_2、0.25mg/L的6-BA对柴胡种子萌发具有明显的抑制作用。     

不同处理方法对白刺花种子萌发的影响

以白刺花种子为试材,采用热水浸种,砂纸摩擦后不同温度浸种、过氧化氢、硝酸钾、赤霉素以及浓硫酸溶液浸种等不同方法处理种子,测定其对白刺花种子吸胀率、发芽势和发芽率的影响.结果表明:砂纸摩擦后不同温度浸种能显著促进白刺花种子的萌发,其中砂纸摩擦后25℃恒温浸种效果最好,发芽势和发芽率分别达到67.67%、74.33%,分别比对照提高了65.67%、69%.     

三种外源物质对镉胁迫下紫花苜蓿种子萌发的影响

为探究镉(Cd)胁迫对紫花苜蓿种子萌发的影响,以及外源物质对Cd胁迫的缓解效果,本研究以维多利亚紫花苜蓿为材料,通过在筛选出的能明显抑制该紫花苜蓿品种种子萌发的Cd浓度下分别用吲哚乙酸(IAA)、水杨酸(SA)和柠檬酸(CA)三种外源物质处理紫花苜蓿种子并检测其萌发情况。结果表明,Cd浓度在100 mg/L以上时对维多利亚紫花苜蓿种子萌发有明显的抑制作用;三种外源物质预处理紫花苜蓿种子均能不同程度的缓解Cd对种子萌发的胁迫;检测的4个萌发指标(发芽率、发芽势、发芽指标和活力指数)中发芽指数无显著变化,不适用于作为指示Cd胁迫缓解的生理指标。     

不同水稻品种种子萌发期耐镉性的研究

采用室内生物测定方法,研究了0.5 mmol/L镉(Cd)胁迫对贵州省主要栽培的32个水稻品种种子的萌发率、发芽指数、活力指数、根长、芽长和鲜质量的影响,并根据综合效应进行了评价。结果表明,Cd对种子发芽率影响较小,对发芽指数、活力指数、根、芽生长的影响显著,且对根的抑制效应大于芽;不同水稻品种种子萌发状况对Cd的响应存在较大的差异。应用快速聚类方法,根据综合效应可以将参试品种划分为耐受型、中间型和敏感型3种不同类型,其中耐性品种有中优5617、II优808、川江优3号,敏感品种有中优9801、冈优725、中优293、黔香优2000、金优425、宜香1979、宜香优101,其他为耐性中等品种。     

镉胁迫对甜高粱种子萌发的影响

本试验用浓度分别为0,2,4,8,16,32 mg/L的镉溶液对3个甜高粱品种(上海甜高粱、意大利甜高粱和兴佳甜高粱)的种子进行胁迫处理,测定了镉胁迫对种子发芽势、发芽率、发芽指数、活力指数、苗长和根长等发芽指标的影响。结果表明,在镉胁迫条件下,3个品种的发芽指标大都随着镉浓度的增加先升高后降低,4 mg/L的镉可以促进甜高粱种子的萌发。在3个参试品种中,上海甜高粱的耐镉性最好。     

聚乙二醇模拟干旱对不同基因型小麦种子萌发的影响

以20%聚乙二醇溶液(PEG-6000)为渗透介质模拟干旱胁迫条件,对4份不同基因型小麦品种进行了种子萌发期抗旱性评价。结果表明:PEG胁迫不同程度的降低了小麦种子的发芽率、发芽指数,其中周麦18降低的幅度最小;和对照相比,PEG胁迫增加了幼苗的相对电导率,不同基因型品种原生质膜受到的损伤程度不同,郑麦9023原生质膜损伤程度最大。各项指标综合分析表明:周麦18具有最强的抗旱性,豫麦49与矮抗58的抗旱性中等,郑麦9023抗旱性较弱,但也有一定的抵御能力。     

Temperature effects on seed germination and expression of seed dormancy in wheat

Because preharvest sprouting decreases quantity and quality of wheat grain, researchers need effective protocols to assess response to preharvest sprouting conditions. The aim of this study was to determine which temperature gives the greatest difference in seed germination and expression of seed dormancy in 10 spring wheat genotypes. The genotypes were grown in the field near Swift Current, Saskatchewan in 2000 in a randomized complete block with four replicates. Seed samples were harvested at approximately 25% moisture content (wet weight basis) and dried to 12% moisture content with minimal after-ripening. Germination was under controlled environment at temperatures of 10, 15, 20 and 30 °C in darkness. A weighted germination index (WGI) was calculated. The analysis of WGI, for each temperature, showed highly significant (p ≤ 0.01) genotype effects on germination. Most genotypes decreased in WGI (increased dormancy) as temperature was increased from 10 to 30 °C. The greatest differences in seed germination tended to be at 15 °C and 20 °C. The level of seed dormancy depended on the genotype and germination temperature. This revised version was published online in August 2006 with corrections to the Cover Date.     

The effects of cis-trans ABA on embryo germination and seed dormancy in wheat

Pre-harvest sprouting of wheat grain can cause economic losses especially in cultivars with low levels of seed dormancy. The aim of this study was to determine genotype differences in embryo sensitivity to germination in response to exogenous (+/–) cis-trans ABA treatments at different concentrations. Six white and four red seed-colored bread wheat genotypes that differed in dormancy were grown in a field near Swift Current, Saskatchewan in 2000 as a randomized complete block design with four replicates. The seed samples from this experiment were germinated in a controlled environment at 20 °C without light. The exogenous ABA treatments were 0 μM – whole seed (control), 0 μM-embryos, 25 μM – embryos and 50 μM – embryos. The ABA experiment was a factorial design with four randomized complete blocks with four ABA treatments in all combinations with the ten genotypes. A weighted (by day) germination index (WGI) was calculated for each genotype in each ABA treatment. Genotypes differed in response to ABA. The genotypes, ABA concentration and genotype by ABA concentration interaction effects were significant (p ≤ 0.05). Excised embryos showed significantly decreased dormancy in most of the experimental genotypes. The addition of exogenous ABA enhanced embryo dormancy of most genotypes. This revised version was published online in August 2006 with corrections to the Cover Date.     

Relationships between cold- and salt-tolerance during seed germination in tomato: Germplasm evaluation

Thirty tomato accessions representing six Lycopersicon species were evaluated for the rate of seed germination under no stress, cold-stress and salt-stress conditions. Most accessions responded similarly to both cold- and salt-stress conditions (i.e. they were equally sensitive or tolerant to both stresses), however, a few accessions exhibited more sensitivity (or tolerance) to one stress than the other. In addition, some accessions that germinated relatively rapidly under non-stress conditions exhibited great sensitivity to both cold stress and salt stress. Across accessions, significant (P < 0.01) positive phenotypic correlations were observed between germination rate under control and cold stress (r_P= 0.89), control and salt stress (r_P= 0.63) and cold stress and salt stress (r_P= 0.77). The results indicate that the rate of tomato seed germination under non-stress, cold- and salt-stress conditions may be controlled by the same genes (or physiological mechanisms), but additional components may be involved which affect germination rate under specific stress conditions.     

盐胁迫对不同油菜种子萌发的影响

为明确5种饲料油菜对新疆盐碱土壤的适应性,研究不同浓度(0、50、100、150、200、250 mmol·L-1)的盐(NaCl)胁迫对华油杂62、饲油2号、福油128、金油杂158、福油158等5个饲料油菜种子萌发、生长指标的影响.结果显示,不同浓度的盐溶液对5种饲料油菜种子发芽的抑制程度不同,随盐溶液浓度的增加,...     

Varietal variation and physiological basis for inhibition of wheat seed germination after excessive water treatment

Soaking the seeds of most upland plants in water before sowing results in poor germination. Varietal differences in flooding tolerance of seeds have been reported in maize, soybean, barley and so on. This study was conducted to evaluate the varietal difference in wheat (2n = 42) seeds to soaking injury and to examine the importance of ethanol accumulation and seed coat as determinants of flooding tolerance. Of 342 varieties tested, many from Asia appeared more tolerant of flooding than the varieties from the Middle East. Soak-induced inhibition of germination and amounts of ethanol excreted were increased with soaking duration. Seeds of 26 wheat varieties were soaked 8 days at 20 °. Subsequent germination was correlated with amounts of ethanol excreted. Seeds with a red-colored coat exhibited higher tolerance to flooding than white ones, however, a varietal difference existed even in the case where the seed coat was peeled. These data suggest that soak-induced inhibition of wheat seed germination relates to accumulation of ethanol rather than seed coat color. This revised version was published online in July 2006 with corrections to the Cover Date.     

Absence of a genetic relationship between salt tolerance during seed germination and vegetative growth in tomato

Two approaches were used to determine the relationship between salt tolerance during seed germination and vegetative growth in tomato. First, F₄ progeny families of a cross between a breeding line, ‘UCT5’ (salt sensitive at all developmental stages), and a primitive cultivar, ‘PI 174263’ (salt tolerant during germination and vegetative growth), were evaluated in separate experiments for salt tolerance during germination and vegetative growth. There were significant differences among the F₄ families in both the rate of seed germination and the plant growth (dry matter production) under salt stress. There was, however, no significant correlation between the ability of seeds to germinate rapidly and the ability of plants to grow under salt stress. In the second approach, selection was made for rapid germination under salt stress in an F₂ population of the same cross and the selected progeny was evaluated for salt tolerance during both germination and vegetative growth. The results indicated that selection for salt tolerance during germination significantly improved germination performance under salt stress; a realized heritability estimate of 0.73 was obtained. Selection for salt tolerance during germination, however, did not affect plant salt tolerance during vegetative growth; there was no significant difference between the selected and unselected progeny based on either absolute or relative growth under salt stress. Obviously, in these genetic materials, salt tolerance during germination and vegetative growth are controlled by different mechanisms. Thus, to develop tomato cultivars with improved salt tolerance, selection protocols that include all critical developmental stages would be desirable.     

重金属镍胁迫对小麦种子萌发及幼苗生长的影响

研究了不同浓度(0.5、1、5、10、50、100 mg/L)镍(Ni2+)处理对小麦种子萌发和幼苗生长的影响..结果表明,低浓度(≤5mg/L)有利于小麦种子的萌发及幼苗生长,中等浓度(5 ～ 10 mg/L)时能正常萌发和生长,而高浓度(＞10 mg/L)则对其有明显的抑制作用,且随浓度增大抑制作用逐渐增强.相对于高浓度Ni2对芽的长度和重量的抑制作用,对根的长度和重量的抑制作用更大.     

Genetic variation in wheat cadmium accumulation on soils with different cadmium concentrations

Cadmium (Cd) accumulation in wheat genotypes of spring bread wheat (Triticum aestivum L.) and spring durum wheat (Triticum turgidum var. durum) was studied in field trials every third week throughout the growing season. The study was carried out in Sweden on three different soils and during two growing seasons. The results showed that the genetic variation in shoot and grain Cd accumulation remained consistent, regardless of soil type or growing season. In addition, it was possible to select the genotype that accumulated most Cd already at the beginning of the growing season, since this genotype also accumulated most Cd in the vegetative tissues of the shoot. These results indicate that it is possible to identify genotypes that accumulate most Cd in the grain at an early plant development stage. High Cd concentrations in the shoot were also observed to give high Cd concentrations in the grain. This indicates that the regulatory mechanism for grain Cd accumulation is not located in the shoot, but in the root or as a feature of root Cd uptake. The soil material and the soil solution at all three sites were analysed for strongly bound Cd (as extracted with 2 m HNO₃), more easily plant‐available Cd (as extracted with ammonium lactate), pH, organic matter, clay content and conductivity. None of these parameters was clearly correlated to the Cd concentration in the grain.     

不同盐分胁迫对盐地碱蓬种子萌发的效应

用不同浓度的单盐NaCl和混合盐溶液（2.9g/L,5.9g/L,11.7g/L,17.6g/L,23.4g/L,35.1g/L）处理盐生植物盐地碱蓬种子,以研究不同盐分对盐生植物种子萌发的影响。结果表明,随着盐浓度的增加,种子的萌发率降低,萌发率与处理盐浓度呈显著的负相关关系,NaCl和混合盐溶液中相关系数分别为0.96和0.94;盐地碱蓬种子在蒸馏水中萌发率最高,并且单盐NaCl对种子萌发的抑制作用大于混合盐溶液;未发芽的种子转至蒸馏水中后最终萌发率都达到了对照种子的85%以上,表明盐胁迫下种子仍保持较高的萌发潜力;种子萌发恢复率与处理盐浓度之间呈正相关关系。     

Tolerance of barley seed germination to cold- and drought-stress expressed as seed vigour

In barley, high seed vigour is a precondition for rapid and homogenous field emergence and good malting quality. Seed vigour was defined as germination percentage under stress conditions (10°C, drought stress ‐ 2 Bars) in 7‐8 barley varieties grown in 7‐8 locations in the Czech Republic over 7 years. Three of the 7 years were not suitable for high seed quality, probably because of unsuitable weather, as average seed vigour reached only 61, 77 and 86%, respectively. In the remaining 4 years, the average vigour exceeded 94%. The impact of variety on seed vigour was higher in the ‘bad years’ and the impact of location was higher in the other years. Varieties with higher vigour from all locations in the ‘bad years’ were identified. Lower vigour was related to the high occurrence of fungi (indicated by ergosterol assays) and to lower field emergence rates of seed samples. The results support the possibility of selecting for improvement of barley seed vigour, which is related to tolerance to various conditions during emergence and to homogenous malting.