共查询到19条相似文献，搜索用时 546 毫秒
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实验结果表明:①甜菜营养生长不同时期耐旱力不同,块根分化形成期为干旱敏感期。②甜菜不同类型品种的耐旱力有差异,在供试品种中,四倍体品种耐旱力较弱;高糖型二倍体品种较丰产型二倍体品种耐旱。③不同类型品种的耐旱力与其生理生化特性有关,耐旱品种在干旱胁迫下有较低的电解质外渗率,较高的超氧化物歧化酶、过氧化氢酶活力,较低的枯叶/全叶比值和较短的暂时萎蔫时间。④在严重的干旱胁迫下,在块根产量、含糖率、产糖量3个方面,四倍体品种与二倍体品种差异不显著,在二倍体品种内,高糖型品种与丰产型品种之间的差异接近或达到显著、极显著水平。 相似文献
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利用核磁共振技术测定了生长在水分胁迫和非胁迫条件下的２０个小麦品种不同生长阶段叶水分子自旋一晶格张驰时间Ｔ１．从而确定它们的耐旱性。这种测定是在盆栽和大田生长的植株上进行的．叶水分含量、相对水分含量以及叶水势与叶水分子张驰时间Ｔ１具有很强的相关性。耐旱小麦品种叶水分子张驰时间Ｔ１比敏感品种的Ｔ１显著的高．无论生长条件怎样。发现在作物处于分率期不同小麦基因型的Ｔ１值变化最大。因此．分荣期叶子水分Ｔ１值的测定为评价小麦耐旱基因型提供了一个快速测定途径． 相似文献
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利用核磁共振技术测定了生长在水分胁迫和非胁迫条件下的２０个小麦品种不同生长阶段叶水分子自旋－晶格张驰时间Ｔ１，从而确定它们的耐旱性，这种测定是在盆栽和大田生长的植株上进行的。叶水分含量、相对水分含量及以叶水势与叶水分子张驰时间Ｔ１具有很强的相关性。耐旱小麦品种叶水分子张驰时间Ｔ１比敏感品种的Ｔ１显著的高，无论生长条件怎样。发现在作物处于分蘖期不同小麦基因型的Ｔ１值变化最大。因此，分蘖期叶子水分Ｔ１ 相似文献
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茶树品种的优质性状受遗传基因所支配,也受气候条件、地理环境、土壤和培植等因素的影响。通常在栽培环境一致条件下,比较它们芽叶性状间的差异,明确优质种性的选择方向,对于品质育种具有重要意义。 本研究针对安徽地方有性群体及祁门群体中选育出的无性系,在同一环境下的二个区组试验,对其经济性状与适制性及成茶品质进行相关分析。 一、不同品种<品系>茶树的芽叶特征与适制性的关系 不同品种(品系)茶树的芽叶性状特征及其成茶品质表现见表一、二。表一是无性系(选择的个体水平),表二是有性系(群体的 相似文献
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在本试验的初步研究中调查了用抗旱的无性系茶树在嫁接中做砧木,以增强高产但不抗旱的无性系茶树的耐旱力的可能性。 众所周知,在干旱丘陵茶区的高产无性系品种如2023和2026抗旱性总是差于低产无性系品种如DN、2025和CY-9。近期的研究已揭示出茶树无性系品种抗旱性不同的一个重要因素是由于它们的根系生长的深度不同(Nagara- 相似文献
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制约茶树叶片水势的部分因素分析 总被引：1，自引：0，他引：1
以阿贝折射仪观测法系统测定了在不同种植密度、修剪程度、品种季节下茶树叶片组织的水势。发现水势随叶片含水量减少、种植密度增大和修剪程度加重而降低，盛夏水势低于严冬。 相似文献
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低氮对不同茶树品种叶绿素荧光特性的影响 总被引：1，自引：0，他引：1
叶绿素荧光参数经常用来评价植物抗逆胁迫强弱,反应植物胁迫的生理状态等。为灵敏检测和判断茶树品种低氮胁迫的差异,科学指导施肥,本研究以前期筛选的相对氮高效茶树品种黄旦与相对氮敏感茶树品种本山为试验材料,检测不同供氮处理下叶绿素荧光参数及生物量的变化,结果发现低氮条件下茶树叶片氮含量显著偏低,但该条件下黄旦品种叶片氮含量明显高于本山品种;低氮条件下茶树叶片最小荧光F_o、调节性能量耗散的量子产额Y(NPQ)、非光化学淬灭系数(NPQ)、非调节性能量耗散的量子产额Y(NO)等显著增加,黄旦品种在低氮条件下F_o、Y(NPQ)、Y(NO)及NPQ参数都要小于本山品种;而参数最大荧光(F_m)、光系统Ⅱ最大光合效率(F_v/F_m)、光化学淬灭系数(qP与qL)、实际光合效率Y(Ⅱ)显著下降,其中本山品种低氮下明显小于黄旦。总之,氮高效茶树品种黄旦能减缓低氮胁迫对植株造成的损害,并维持相对较高的光合效率,保证了低氮条件下有较高的产量。 相似文献
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《Field Crops Research》2005,91(2-3):231-249
Drought is the most important limitation to sugar beet (Beta vulgaris L.) production in the UK and other areas dependent on usually insufficient summer rainfall. As increased irrigation is not a viable answer to the problem, an economically and environmentally desirable solution is new varieties with decreased sensitivity to water deficits. However, there is little genotypic information on drought tolerance in sugar beet, and breeders are not equipped to make these selections. The objectives of this study were to assess the degree of genotypic diversity for drought-related morpho-physiological traits and to measure the strength of association between these traits and indicators of crop performance. 46 sugar beet genotypes with diverse genetic backgrounds were tested in three field experiments from 1999 to 2001. Drought was imposed by covering plots with large polythene tunnels, allowing the crop to grow solely on stored soil moisture. Agronomic characters and drought tolerance indices are described in a companion paper [Ober et al., Assessing the genetic resources to improve drought tolerance in sugar beet. Agronomic traits of diverse genotypes under droughted and irrigated conditions. Field Crops Res., in press]. In this report, we show that there were significant genotypic differences for stomatal conductance, succulence index, specific leaf weight, and osmotic adjustment, but not for photosynthetic rate, relative water content or total water use. Patterns of water use within the soil profile differed between genotypes; some extracted more water from deep soil layers. The maintenance of green foliage cover during drought was positively correlated with drought tolerance index, which was negatively correlated with succulence index and scores for wilting and leaf senescence. Droughted sugar yield was positively correlated with soil water extraction and negatively correlated with relative leaf expansion rate measured in late summer. Under irrigated conditions, there was high positive correlation between transpiration rate and sugar yield. Genotype × trait biplots showed superior genotypes with relatively greater expression of combinations of favourable traits. The results suggest that succulence index and wilting score could be used to cull inferior plants in early stages of breeding programs, and green foliage cover and patterns of water use could help identify superior genotypes in elite germplasm. These data should enable tools to be developed for indirect selection of genotypes suited to drought-prone environments. 相似文献
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以3个海滨雀稗(Paspalum vaginatum)品种(Sea Isle2000、Platinum、Supreme)及其经辐射诱变筛选出的7个突变体为试验材料,在干旱胁迫条件下通过测定叶片相对含水量(RWC)、叶片相对电导率(REC)、脯氨酸(Pro)含量、可溶性总糖含量(TSC)及叶片萎蔫系数等5个生理指标,综合评价其抗旱性。结果表明:干旱胁迫导致试验材料的RWC下降,叶片萎蔫系数、Pro、TSC、REC上升,但不同品种材料的变化幅度不同。突变体"PL-40-1"、"PL-40-2"、"SP-40-2"在干旱胁迫下,其RWC下降幅度显著低于对照,叶片萎蔫系数、Pro、TSC、REC的上升幅度均明显低于对照,说明突变体"PL-40-1"、"PL-40-2"、"SP-40-2"叶片的保水能力较强,抗旱性优于其亲本;而突变体"SI-50-1"、"SI-50-5"、"SI-60-6"、"PL-40-8"抗旱性不及其亲本。 相似文献
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Warren K. Coleman 《American Journal of Potato Research》1986,63(5):263-276
Physiological responses to drought stress were evaluated in the potato cultivars Raritan and Shepody. Under well-watered conditions, Raritan exhibited a higher transpiration rate than Shepody. This higher rate could be related to a lower calculated stomatal resistance on abaxial leaf surfaces. Under drought stress conditions, Raritan consistently demonstrated superior performance over Shepody in the following areas: leaf water retention, epicuticular wax levels, desiccation tolerance and root growth. The estimated relative water content at a leaf water potential of-1.0 MPa was higher for Raritan than Shepody regardless of leaf age and may indicate a greater drought resistance in the former cultivar. 相似文献
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以6种不同干旱耐性玉米自交系为研究对象,开展不同自交系苗期干旱耐性、泡状细胞特性及干旱胁迫后泡状细胞形变等研究,揭示泡状细胞与干旱胁迫耐性差异玉米自交系干旱胁迫前后的特性及反应的关联性,在细胞水平上探索重要农作物干旱胁迫反应机制。结果表明,玉米自交系B73、PH4CV、HiC对干旱胁迫较为敏感,Mo17干旱耐性较强,Zong31、Z58次之。泡状细胞切片显示,叶片表皮泡状细胞簇数随自交系干旱耐性增强而增多,每簇泡状细胞数量随自交系干旱耐性增强而减少。干旱处理后,泡状细胞发生明显形变,自交系泡状细胞形变程度与其干旱耐性、叶片萎蔫程度、红外热成像、组织含水量和膜脂氧化产物MDA(Malondialdehyde)积累等胁迫反应特征呈对应关系,表明玉米叶片泡状细胞在调节植物干旱胁迫反应中发挥重要作用。 相似文献
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模拟阴坡鱼腥草对梯度水分变化的响应 总被引：1，自引：0，他引：1
设置重度干旱、中度干旱、轻度干旱、轻度湿润、中度湿润、重度湿润、水淹及对照8个水分梯度，研究模拟自然阴坡环境土壤水分梯度对鱼腥草（Houttuynia cordata Thunb）生长和生理水平的影响。结果表明：重度干旱显著抑制鱼腥草茎叶含水量、生物量，但明显提高根冠比；重度干旱和中度干旱明显降低根状茎和根的含水量、株高、根长和叶面积指数，根数增加；水淹时，显著提高茎叶含水量，根数减少，根长增加。过氧化氢酶（CAT）和过氧化物酶（POD）活性对水分变化响应不明显，而超氧化物歧化酶（SOD）活性具有较显著的敏感性，水分的增加或减少均显著提高SOD活性。中等程度以上的干旱或湿润均显著提高丙二醛（MDA）含量。除轻度湿润组外，叶绿素含量随干旱或湿润胁迫程度的加剧明显依次下降，显著响应梯度水分变化。重度湿润时，MDA含量、相对膜伤害率、抗氧化酶活性最高，且叶绿素含量较低，表明其受到了严重水渍胁迫。综上所述，模拟阴坡条件下，轻度干旱和中度湿润之间的水分条件更加适宜于鱼腥草的栽培。 相似文献
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干旱胁迫下玉米自交系叶片木质素含量变化及其与耐旱性的关系 总被引：1，自引：0，他引：1
选用耐旱性不同的6个玉米自交系,在不同干旱胁迫强度及正常灌水条件下,测定叶片的木质素含量,并转换为耐旱系数,研究其与雌雄花期间隔和单株子粒产量耐旱系数的相关性。结果表明,耐旱性不同的自交系叶片的木质素含量对干旱胁迫的反应不同。在干旱胁迫条件下,耐旱性较强的自交系木质素含量显著升高,平均耐旱系数较大,耐旱性中等的自交系木质素含量比正常灌水对照略有升高,耐旱性较弱的自交系木质素含量与对照相当或下降。在中等干旱和严重干旱条件下,叶片木质素含量平均耐旱系数与单株子粒产量和雌雄花期间隔耐旱系数的相关系数分别为r=0.848和r=0.889,均达显著水平。 相似文献
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为了明确土壤长期持续干旱对冬小麦生理状况和生长发育的影响，采用盆栽方法，对长期持续不同土壤干旱条件下冬小麦水分生理和生物量的分配进行了初步研究。结果表明，随土壤水分的减少，冬小麦蒸腾速率、叶水势、叶片相对含水率、耗水量、耗水系数等水分生理指标均呈降低趋势，饱和亏呈递增趋势；地上部干物质量和总干重递减，根系量除轻度干旱处理最大外，其他各处理递减，根冠比递增。这说明，冬小麦随土壤水分的减少抗旱性增强，低土壤水分有利于增大光合产物向根系的分配，高土壤水分则有利于地上部发育。 相似文献
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《Field Crops Research》2002,73(2-3):181-200
A series of experiments were conducted in drought-prone northeast Thailand to examine the magnitude of yield responses of diverse genotypes to drought stress environments and to identify traits that may confer drought resistance to rainfed lowland rice. One hundred and twenty eight genotypes were grown under non-stress and four different types of drought stress conditions.Under severe drought conditions, the maintenance of PWP of genotypes played a significant role in determining final grain yield. Because of their smaller plant size (lower total dry matter at anthesis) genotypes that extracted less soil water during the early stages of the drought period, tended to maintain higher PWP and had a higher fertile panicle percentage, filled grain percentage and final grain yield than other genotypes. PWP was correlated with delay in flowering (r=−0.387) indicating that the latter could be used as a measure of water potential under stress. Genotypes with well-developed root systems extracted water too rapidly and experienced severe water stress at flowering. RPR which showed smaller coefficient of variation was more useful than root mass density in identifying genotypes with large root system.Under less severe and prolonged drought conditions, genotypes that could achieve higher plant dry matter at anthesis were desirable. They had less delay in flowering, higher grain yield and higher drought response index, indicating the importance of ability to grow during the prolonged stress period.Other shoot characters (osmotic potential, leaf temperature, leaf rolling, leaf death) had little effect on grain yield under different drought conditions. This was associated with a lack of genetic variation and difficulty in estimating trait values precisely.Under mild stress conditions (yield loss less than 50%), there was no significant relationship between the measured drought characters and grain yield. Under these mild drought conditions, yield is determined more by yield potential and phenotype than by drought resistant mechanisms per se. 相似文献