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1.
This study aimed to reduce the gap of knowledge on white lupin drought tolerance variation, by assessing the grain yield of 21 landraces from major historical cropping regions, one variety and two breeding lines in a large phenotyping platform that imposed controlled severely stressed or moisture‐favourable conditions after an initial stage of favourable growth. Drought stress reduced grain yield by 79%. Genetic correlation coefficients indicated moderate consistency of genotype responses across conditions for grain yield (rg = 0.76), fairly high consistency for straw yield (rg = 0.85) and harvest index (rg = 0.91), and high consistency for flowering time (rg = 0.99). However, low genetic correlation for yield (rg = 0.31) occurred among a subset of genotypes with early phenology. Specific adaptation to either condition implied significant (p = 0.05) genotype × condition interaction of crossover type between well‐performing genotypes. Early flowering was an important stress escape mechanism, but intrinsic drought tolerance could be inferred from responses of a few genotypes. Various landraces out‐yielded the improved germplasm under stressed or favourable conditions.  相似文献   

2.
干旱是一个世界性问题,也是造成中国作物产量低的重要原因。为探究干旱胁迫对马铃薯生理的影响和鉴定耐旱材料,本研究以‘青薯9号’和‘陇薯5号’两基因型马铃薯组培苗为试材,用0%、10%、20%、30%和40%浓度(m/V)的PEG-6000胁迫96 h模拟干旱筛选适宜的胁迫浓度,在含有适宜胁迫浓度的培养液中培养0、20、24、48、72和96 h后,测定抗氧化酶活性、可溶性物质和丙二醛(MDA)含量的变化,最后利用差异变化的生理指标的抗旱系数及主成分分析综合评价马铃薯耐旱能力。结果表明:20%浓度PEG-6000是适宜的胁迫浓度。干旱胁迫处理后,与对照相比,‘陇薯5号’超氧化物歧化酶(SOD)有显著增加,过氧化物酶(POD)和丙二醛(MDA)没有显著差异,可溶性糖在20 h开始显著增加;‘青薯9号’SOD没有显著变化,POD活性显著下降,可溶性糖72 h显著增加,MDA含量没有显著变化。7项生理指标可作为鉴定指标进行主成分分析综合评价,并提取出3个主成分,累积贡献率达79.2%,综合得分评价结果表明,‘陇薯5号’的综合耐旱能力强于‘青薯9号’。本研究对马铃薯干旱胁迫生理特性及耐旱性进行深入研究以及培育耐旱性马铃薯具有重要意义。  相似文献   

3.
Drought tolerance is one of the most important objectives of sugar beet breeding programs in semi-arid regions, particularly during the last decade. Due to global climate changes and limitations of agricultural irrigation water, varieties with drought tolerance are taken into consideration in order to avoid yield losses due to drought. In this study, drought tolerance of 76 S1 lines (full-sib families) that had been extracted from a genetically broad base multigerm sugar beet open pollinated population, were examined. Test crosses were made between the lines as pollinators and a cytoplasmic male sterile (CMS) single cross. The consequent hybrids along with checks were evaluated during 2007 and 23 more tolerant hybrids during 2008, in two adjacent experiments under drought stress and non-stress conditions. Drought tolerance indices calculated based on sugar yield, such as mean productivity (MP), geometric mean productivity (GMP) and stress tolerance index (STI) were used to assess hybrids responses to drought. The results showed significant genetic differences for root yield and sugar yield under both conditions. Drought tolerance indices displayed significant genetic variability for sugar yield among the hybrids. Many hybrids were drought tolerant as compared with the original base population as indicated by their high STI. The estimates of heritability for sugar yield in stress and non-stress conditions were much close to each other (0.31 and 0.34, respectively). Whereas, for root yield the heritability estimate in stress condition (0.46) was relatively higher than that in non-stress condition (0.34). Significant differences were observed among the selected hybrids for root yield and sugar yield, indicating genotypic variability for pollinator lines derived from the population. There were no significant differences for sugar content. For increasing the drought tolerance potential in a breeding population and developing drought-tolerant varieties by male parent, the drought-tolerant lines could be used.  相似文献   

4.
This paper describes experiments concerning improvement of drought tolerance in narrow‐leafed lupine (Lupinus angustifolius L.) by maternal effects. The first step involved harvesting seeds from plants exposed and not exposed to drought during flowering and seed ripening. The next‐generation plants grown from these seeds were exposed to drought and the effects of this stress on their physiological processes were examined. To find out whether drought applied to parent plants may affect tolerance to this stress in progeny plants such features as plant growth, tissue water content, abscisic acid concentration and yield‐related parameters were assessed. The study revealed that the progeny plants grown from the seeds of drought‐treated plants were more tolerant to this stress than the plants grown from the seeds harvested from optimally watered maternal plants. Drought tolerance was manifested by a reduced concentration of abscisic acid, increased plant height and maintaining high leaf water content. Most importantly, these plants produced significantly higher yield when exposed to drought than the plants grown from the seeds harvested from optimally watered plants.  相似文献   

5.
Solanum tuberosum (potato) as a drought sensitive plant is also one of the most promising plants to meet the demands for food and starch of a growing population. Distinguishing genotypes into tolerant and susceptible is therefore of utmost interest. We subjected eighteen potato genotypes and two wild species, S. tarijense and S. chacoense, to osmotic stress applied in vitro by addition of 0.2 m sorbitol to a solid medium. Here, we report that a ratio of root:shoot dry mass (DM) together with the SSI (stress susceptibility index, equivalent to drought susceptibility index by Fischer and Maurer, Aust. J. Agron. Res., 29, 1978) of shoot DM were found to be relevant parameters to characterize genotypes in vitro for their osmotic stress tolerance. Drought stress data from pot trials in a rainout shelter (2013 and 2015) correlated poorly with the data obtained in in vitro experiments. However, the most tolerant and most sensitive genotypes in vitro were also categorized to be more tolerant or sensitive than the average to drought stress in vivo. Both, under in vitro and in vivo conditions, proline displayed an increase under osmotic stress conditions in nearly all potatoes tested, but no direct correlations were found to stress tolerance. However, a genotype classified as tolerant displayed earlier proline accumulation. Proline is thought of as one factor for plants to withstand stressful conditions, but cannot be used to distinguish potato genotypes for their stress tolerance to osmotic stress in vitro. Analysis of the osmotic potential of in vitro and in vivo stressed plants displayed a general increase compared to the control.  相似文献   

6.
The physiological basis of genetic variation in drought response and its association with yield and related indices is not clear in tall fescue. In this study thirty genotypes of tall fescue (Festuca arundinacea Schreb.) were sampled from a polycross population and evaluated under two levels of irrigation in 2010 (normal and intense stress) and 2011 (normal and mild stress). Physiological traits including relative water content (RWC), total chlorophyll (TChl), chlorophyll a (Chla), chlorophyll b (Chlb), Chla/Chlb, carotenoids (Car), TChl/Car and proline content along with forage yield, agro-morpholgical traits and selection indices (stress tolerance index, STI and drought susceptibility index, DSI) were studied. Large variation and moderate to high heritability was estimated for most of the studied traits. Intense drought condition decreased chlorophyll content while mild stress significantly increased it. In the other hand intense drought stress increased Chla/b while mild stress didn’t change it. Under mild drought stress condition STI was positively correlated with RWC while under intense drought stress condition STI was positively correlated with chlorophyll content. Although proline content was significantly increased in both intense and mild drought stress conditions, no relationship was found between proline accumulation with forage yield and STI. Applications of principle component analysis for screening suitable genotypes are also discussed.  相似文献   

7.
Heat stress resulting from climate change and more frequent weather extremes is expected to negatively affect wheat yield. We evaluated the response of different spring wheat cultivars to a post‐anthesis high temperature episode and studied the relationship between different traits associated with heat tolerance. Fifteen spring wheat (Triticum aestivum L.) cultivars were grown in pots under semifield conditions, and heat stress (35/26 °C) and control treatments (20/12 °C) were applied in growth chambers for 5 days starting 14 days after flowering. The heat stress treatment reduced final yield in all cultivars. Significant variation was observed among cultivars in the reduction in average grain weight and grain dry matter yield under heat stress (up to 36 % and 45 %, respectively). The duration of the grain‐filling period was reduced by 3–12 days by the heat treatment. The reduction in the grain‐filling period was negatively correlated with grain nitrogen yield (r = ?0.60). A positive correlation (r = 0.73) was found between the treatment effect on green leaf area (GLA) and the reduction in yield resulting from heat stress. The amount of stem water‐soluble carbohydrates (WSC) was not related to treatment effects on grain yield or grain weight. However, the treatment effect on stem WSC remobilization was negatively correlated with reduction in grain‐filling duration due to heat stress (r = ?0.74) and positively with treatment effect on grain N yield (r = 0.52). The results suggest that the effect of the heat treatment on GLA was the trait most associated with yield reduction in all cultivars. These findings suggest the importance of ‘stay green’‐associated traits in plant breeding as well as the need for better modelling of GLA in crop models, especially with respect to brief heat episodes during grain filling. There is in particular a need to model how heat and other stresses, including interacting effects of heat and drought, affect duration of GLA after flowering and how this affects source–sink relations during grain filling.  相似文献   

8.
Selection for drought tolerance entails prioritizing plant traits that integrate critical physiological processes occurring during crop growth. Discrimination against 13C (?) in leaflets (?leaflet) and tubers (?tuber) was compared under two water regimes in two potato‐improved varieties selected to maintain yield under drought conditions (Unica and Sarnav) and one drought susceptible European cultivar (Désirée). In the control treatment, soil water content was kept at field capacity over the whole growth cycle, while in the drought treatment water supply was restricted after tuber initiation (50 % of field capacity). Gas exchange and N content per unit leaf area (Narea) as well as ? were assessed at different stages. Sarnav showed the highest tuber yield in both water conditions, suggesting that yield in the water restriction treatment was largely driven by yield potential in this genotype. Higher stomatal conductance (gs) and Narea and lower ?leaflet in well‐watered Sarnav suggested higher photosynthetic capacity. Under water restriction, Sarnav maintained higher gs indicating that carbon diffusion was a key factor for biomass accumulation under water restriction. Our results suggest the use of ? determined after tuber initiation as an indirect selection indicator for tuber yield under both well‐watered and restricted soil water availability conditions.  相似文献   

9.
Improved adaptation of potato to limited water availability is needed for stable yields under drought. The maintenance of the cell water status and protection of cellular components against dehydration are important for drought tolerance, and the N status of plants affects the regulation of various respective metabolic processes. A 2‐year pot trial with 17 potato cultivars was conducted under a rain‐out shelter including two water regimes and two N‐levels to investigate genotypic differences concerning osmotic adjustment (OA) and relevant biochemical traits in relation to nitrogen (N) supply. Drought stress resulted in a rapid decrease in the leaf osmotic potential. The N, protein and proline contents increased under drought, while the N protein/NKjeldahl ratio decreased. Initially, total soluble sugars increased at both N‐levels but dropped back to the control level at high N‐availability under prolonged drought while remaining high in N‐deficient plants. Results indicate that potatoes have only a limited capacity of active OA and that increasing sugar and proline concentrations are rather associated with the protection of cellular components. High N supply promoted the N protein/NKjeldahl ratio at short‐term drought and enhanced proline accumulation. Significant genotypic differences were observed for all investigated traits.  相似文献   

10.
Drought tolerance is an increasingly important trait in common bean ( Phaseolus vulgaris L.) due to the reduction in water resources, a shift in production areas and increasing input costs. The objective of this study was to evaluate 29 genotypes for drought tolerance under drought stress (DS) and reduced stress treatments in Juana Diaz, Puerto Rico. The use of DS and reduced stress treatments facilitated the identification of drought tolerant germplasm that also had good yield potential under more optimal conditions. Based on the results of seed yield under DS and reduced stress conditions, and DS indices, including the geometric mean (GM), stress tolerance index (STI) and percent yield reduction (YR), genotypes were identified with greater yield potential under the tested environment. Based on average GM over the 2 years, the superior common bean genotypes identified were SEA 5, G 21212, A 686, SEN 21 and SER 21. These genotypes performed well in both years and under both treatment conditions and thus may serve as parents for DS improvement and genetic analysis.  相似文献   

11.
不同棉花品种对干旱胁迫的生理响应及抗旱性评价   总被引：1，自引：0，他引：1  
旨在研究干旱胁迫对不同棉花品种脯氨酸、可溶性糖、丙二醛、过氧化氢酶等生理生化指标的影响。采用田间人工模拟干旱法,设置干旱胁迫和正常浇水2个处理,运用隶属函数法综合评价品种抗旱性强弱。结果表明,干旱胁迫下,棉花叶片脯氨酸、可溶性糖等渗透调节物质的含量增加,过氧化氢酶、超氧化物歧化酶、过氧化物酶保护酶活性提高,抵御干旱的能力增强;棉花的抗旱性是一个复杂的生理生化机制,依据隶属函数综合评价法得出,4份棉花品种的抗旱性强弱依次为‘衡优12’＞‘冀棉958’＞‘中177’＞‘邯杂306’。  相似文献   

12.
为探讨玉米（Zea mays L.）苗期对水分亏缺的响应机制,以抗旱性具有显著差异的2个玉米品种为材料,使用PEG-6000溶液模拟不同强度的干旱胁迫,对逆境中玉米苗期的形态及生理生化特性进行分析。结果表明：干旱胁迫后抗旱性强的成单30的株高、叶面积、根长及根重呈上升趋势,抗旱性弱的金玉306呈下降趋势;干旱胁迫使成单30的地上部干重、根重和干物重等生物产量增加,而金玉306的各生物产量逐渐下降;干旱胁迫导致玉米的丙二醛含量升高,细胞膜稳定性下降,成单30的变化幅度比金玉306小;干旱胁迫使玉米的叶绿素a/b比值及叶绿素含量下降,类胡萝卜素含量增加;成单30的可溶性糖及可溶性蛋白含量在干旱胁迫后变化不显著,而金玉306在后期才出现显著变化;干旱胁迫后,成单30与金玉306的脯氨酸含量均极显著增加;干旱胁迫使玉米的超氧化物歧化酶、过氧化物酶及过氧化氢酶活性提高。这些结果说明不同抗旱性玉米品种的抗旱机制存在一定差异。  相似文献   

13.
Drought stress is a major limiting factor for crop production in the arid and semi‐arid regions. Here, we screened eighty barley (Hordeum vulgare L.) genotypes collected from different geographical locations contrasting in drought stress tolerance and quantified a range of physiological and agronomical indices in glasshouse trails. The experiment was conducted in large soil tanks subjected to drought treatment of eighty barley genotypes at three‐leaf stage and gradually brought to severe drought by withholding irrigation for 30 days under glasshouse conditions. Also, root length of the same genotypes was measured from stress‐affected plants growing hydroponically. Drought tolerance was scored 30 days after the drought stress commenced based on the degree of the leaf wilting, fresh and dry biomass and relative water content. These characteristics were related to stomatal conductance, stomatal density, residual transpiration and leaf sap Na, K, Cl contents measured in control (irrigated) plants. Responses to drought stress differed significantly among the genotypes. The overall drought tolerance was significantly correlated with relative water content, stomatal conductance and leaf Na+ and K+ contents. No significant correlations between drought tolerance and root length of 6‐day‐old seedling, stomatal density, residual transpiration and leaf sap Cl? content were found. Taking together, these results suggest that drought‐tolerant genotypes have lower stomatal conductance, and lower water content, Na+, K+ and Cl? contents in their tissue under control conditions than the drought‐sensitive ones. These traits make them more resilient to the forthcoming drought stress.  相似文献   

14.
Drought is a severe abiotic stress and the major constraint on wheat (Triticum aestivum L.) productivity world wide. Deciphering the mechanisms of drought tolerance is a challenging task because of the complexity of drought responses, environmental factors and their interactions. The objective of this study was to evaluate the ability of the antioxidative defence system in imparting tolerance against drought‐induced oxidative stress and yield loss in two wheat genotypes, when subjected to long‐term field drought. Drought resulted in an increase in H2O2 accumulation and lipid peroxidation and decrease in ascorbate level in roots and leaves at different plant developmental stages. Drought‐tolerant genotype having higher antioxidative enzymes activities, and ascorbate level was superior to that of sensitive genotype in maintaining lower H2O2 content and lipid peroxidation and higher growth, yield and yield components under water deficit. Various antioxidative enzymes showed positive correlation with ascorbate and negative with H2O2 content. In developing grains, antioxidative defence response was nearly similar among both the genotypes under control condition; however, sensitive genotype failed to modulate the activities of antioxidative enzymes according to the ROS rush under field drought. Poor capacity of the antioxidative defence system in vegetative and reproductive tissues of sensitive genotype seems to be responsible, at least partly, for reduced yield potential under water deficit.  相似文献   

15.
Drought during the pre‐flowering stage can increase yield of peanut. There is limited information on genotypic variation for tolerance to and recovery from pre‐flowering drought (PFD) and more importantly the physiological traits underlying genotypic variation. The objectives of this study were to determine the effects of moisture stress during the pre‐flowering phase on pod yield and to understand some of the physiological responses underlying genotypic variation in response to and recovery from PFD. A glasshouse and field experiments were conducted at Khon Kaen University, Thailand. The glasshouse experiment was a randomized complete block design consisting of two watering regimes, i.e. fully‐irrigated control and 1/3 available soil water from emergence to 40 days after emergence followed by adequate water supply, and 12 peanut genotypes. The field experiment was a split‐plot design with two watering regimes as main‐plots, and 12 peanut genotypes as sub‐plots. Measurements of N2 fixation, leaf area (LA) were made in both experiments. In addition, root growth was measured in the glasshouse experiment. Imposition of PFD followed by recovery resulted in an average increase in yield of 24 % (range from 10 % to 57 %) and 12 % (range from 2 % to 51 %) in the field and glasshouse experiments, respectively. Significant genotypic variation for N2 fixation, LA and root growth was also observed after recovery. The study revealed that recovery growth following release of PFD had a stronger influence on final yield than tolerance to water deficits during the PFD. A combination of N2 fixation, LA and root growth accounted for a major portion of the genotypic variation in yield (r = 0.68–0.93) suggesting that these traits could be used as selection criteria for identifying genotypes with rapid recovery from PFD. A combined analysis of glasshouse and field experiments showed that LA and N2 fixation during the recovery had low genotype × environment interaction indicating potential for using these traits for selecting genotypes in peanut improvement programs.  相似文献   

16.
Common bean (Phaseolus vulgaris) is cultivated throughout Latin America and Africa, and for the European community, in Italy and Spain, areas are mainly subjected to drought stress which is predict to worsen by regional climatic models. The aims of this work were to identify the drought‐tolerant and drought‐sensitive bean landraces using drought tolerance and phenotypic plasticity indexes and to dissect the root morphological and 2D‐architecture traits related to drought tolerance. Thirty‐one landraces from diverse gene pools and areas of the Calabria region (South Italy), with different habits and morphological traits, were screened for drought tolerance in a hydroponic system. Root phenotyping was conducted by image analysis. Drought tolerance screening identified two landraces as drought tolerant and sensitive, respectively. Under drought stress, the drought‐tolerant landrace exhibited several interesting root traits such as a higher root length, surface area and, above all, the fineness of the whole root systems and, with emphasis, of the higher order roots. Drought stress induced plastic root responses in both bean landraces but with contrasting patterns. The drought‐tolerant landrace exhibited a dimorphic‐rooted strategy, which could be included in future utility for bean breeding programmes in drought‐prone environments.  相似文献   

17.
Three durum and three bread wheat genotypes were crossed to produce three tetraploid, three hexaploid and nine interspecific (pentaploid) F1 hybrids. All genotypes were evaluated for heat tolerance in the field and for drought using polyethylene glycol in vitro. Chromosome numbers and meiotic behavior in pentaploid F1 hybrids (2n=5x=35, genomes AABBD) were confirmed. Heat stress significantly reduced grain yield/plant and 1000-kernel weight (1000-KW), while grain protein content (GPC) was increased. Drought caused a significant reduction in root length, shoot length and seedling fresh weight, whereas root/shoot ratio was increased. P3 (durum), P4 (bread) and their pentaploid F1 hybrid could be considered as the most heat-tolerant genotypes. However, P2 (durum), P6 (bread) and their F1 were most tolerant to drought. The addition of a D genome single dose into pentaploid F1 hybrids obviously reduced grain yield/plant, 1000-KW and seedling traits, however GPC was increased. Moderate to high broad-sense heritability and genetic advance were obtained for the most investigated traits. Grain yield/plant was strongly positively correlated with stress tolerance index (STI), yield index (YI), mean productivity (MP), geometric mean productivity (GMP) and harmonic mean (HM) under heat stress and with root length under drought condition, suggesting that STI, YI, MP, GMP and HM are powerful indices for heat tolerance, while root length is most effective for drought. Successful interspecific hybridization obtained in the study is only an initial step for desired genes introgression. Successive progenies are going to be evaluated for further genetic studies aiming at improving abiotic stress tolerance in wheat.  相似文献   

18.
Chickpea (Cicer arietinum L.) is a dry season food legume largely grown on residual soil moisture after the rainy season. The crop often experiences moisture stress towards end of the crop season (terminal drought). The crop may also face heat stress at the reproductive stage if sowing is delayed. The breeding approaches for improving adaptation to these stresses include the development of varieties with early maturity and enhanced abiotic stress tolerance. Several varieties with improved drought tolerance have been developed by selecting for grain yield under moisture stress conditions. Similarly, selection for pod set in the crop subjected to heat stress during reproductive stage has helped in the development of heat‐tolerant varieties. A genomic region, called QTL‐hotspot, controlling several drought tolerance‐related traits has been introgressed into several popular cultivars using marker‐assisted backcrossing (MABC), and introgression lines giving significantly higher yield than the popular cultivars have been identified. Multiparent advanced generation intercross (MAGIC) approach has been found promising in enhancing genetic recombination and developing lines with enhanced tolerance to terminal drought and heat stresses.  相似文献   

19.
W. Link    A. A. Abdelmula    E. Von  Kittlitz  S. Bruns    H. Riemer  D. Stelling 《Plant Breeding》1999,118(6):477-484
Instability of yield in faba bean is partly caused by drought susceptibility. Four sets with 10-19 faba bean genotypes each were evaluated in multilocal field trials between 1992 and 1996. Stress occurred as natural drought in one experiment and as artificial terminal drought in three experiments. Artificial drought was induced by rain shelters; the control treatment was irrigated. Tolerance was assessed as the ratio of yield under drought (Yd) to well-watered yield (Yw). Highly significant variances between genotypes occurred; heritability of tolerance was 0.51 < h2 <0.88. Exotic (North African. Latin American) genotypes were more tolerant than adapted material. Correlations between Yw and Yd were 0.77** < r <0.97**, and variance of Yd was less than one-third of the variance of Yw. Drought tolerance was negatively correlated with Yd (-0.41 < r < -0.22). Relative reduction of plant height due to drought was a promising trait to improve drought tolerance indirectly in two sets. The prospects of improving Yd are good: heritability was 0.68 < h2 < 0.86. Genetic improvement of drought tolerance also seems feasible. A specific cross was proposed to create improved material.  相似文献   

20.
To study the effects of early drought priming at 5th‐leaf stage on grain yield and nitrogen‐use efficiency in wheat (Triticum aestivum L.) under post‐anthesis drought and heat stress, wheat plants were first exposed to moderate drought stress (drought priming; that is, the leaf water potential reached ca. ?0.9 MP a) at the 5th‐leaf stage for 11 days, and leaf water relations and gas exchange rates, grain yield and yield components, and agronomic nitrogen‐use efficiency (ANUE ) of the primed and non‐primed plants under post‐anthesis drought and heat stress were investigated. Compared with the non‐primed plants, the drought‐primed plants possessed higher leaf water potential and chlorophyll content, and consequently a higher photosynthetic rate during post‐anthesis drought and heat stress. Drought priming also resulted in higher grain yield and ANUE in wheat under post‐anthesis drought and heat stress. Drought priming at vegetative stage improves carbon assimilation and ANUE under post‐anthesis drought and heat stress and their combination in wheat, which might be used as a field management tool to enhance stress tolerance of wheat crops to multiple abiotic stresses in a future drier and warmer climate.  相似文献   

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