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1.
Thai Hoang Dinh Kenta Watanabe Hiroo Takaragawa Mai Nakabaru 《Plant Production Science》2017,20(4):412-422
Drought stress which often occurs during early growth stage is one constraint in sugarcane production. In this study, the response of sugarcane to drought and nitrogen application for physiological and agronomical characteristics was investigated. Two water regimes (well-watered and drought stress from 60 to 120 day after transplanting) and four nitrogen levels (0, 4.4, 8.8 and 13.2 g pot?1 equivalent to 0, 90, 180 and 270 kg ha?1, respectively) were assigned in a Split-plot design with three replications. The results showed that photosynthetic responses to light intensity and intercellular CO2 concentrations of sugarcane were different between fertilized and non-fertilized treatments. Photosynthetic rates of 180 and 270 N treatments, normally, were significantly higher than that of 90 N, but not significant at drought conditions. Photosynthetic rates of 0 N treatment were the lowest under both conditions. Higher nitrogen application supported higher photosynthetic rate, stomatal conductance, and chlorophyll content because of higher nitrogen concentration accumulated into the leaf. Drought significantly reduced the potential photosynthetic rate, stomatal conductance, SPAD, leaf area, and biomass production. Higher nitrogen applications with larger root system could support higher photosynthetic activities to accumulate more dry mass. Strong positive coefficient between photosynthetic and biomass nitrogen use efficiency and drought tolerance index may suggest that higher nitrogen use efficiency could help plants have higher ability to tolerate drought stress. 相似文献
2.
本研究通过低氮压力选择,筛选出甘蔗氮高效种质,分析影响甘蔗氮高效的重要指标,为甘蔗氮高效育种及栽培提供理论依据。以58份甘蔗种质资源为材料,在苗期采用正常供氮（2 mmol/L N）和低氮（0.2 mmol/L N）处理,分析甘蔗植株形态、干重及氮素在各器官中累积分配的特征。通过主成分分析方法筛选影响甘蔗氮高效利用的重要指标,通过聚类分析对58份种质进行聚类。结果表明,低氮（0.2 mmol/L N）处理可以明显从植物形态区分不同种质的氮利用差异,58份种质低氮条件下的干重范围为0.64~14.75 g/株,氮累积量为5.53~63.00 mg/株,氮利用率范围为115.40~279.30 g/g。对低氮压力下甘蔗干重及氮累积等25个指标进行主成分分析后,提取出4个主要成分,总贡献率为92.35%。通过高、低氮条件下与氮利用效率有关的氮转移系数及基因潜力等19个指标分析后提取出5个主成分,总贡献率为82.21%。影响甘蔗氮高效的重要指标有甘蔗的干重（全株、叶、根）、氮累积量（全株、叶、茎）、氮利用率（全株、叶）、叶的相对氮利用率、茎的基因潜力、茎的相对干物质量和茎的相对氮累积量。经聚类分析后初步将58份甘蔗种质分为氮高效基因型、偏氮高效基因型、偏氮低效基因型和氮低效基因型。 相似文献
3.
ABSTRACTRice (Oryza sativa L.) is one of the most important staple foods in the world, however most improved rice varieties are susceptible to drought stress. A two-year study was conducted to explore the effects of various drought stresses and subsequent recovery on the accumulation and degradation of proline, total soluble sugar and starch in different rice varieties at vegetative stage. The results showed that relative water content in the leaves and sheaths of rice varieties significantly decreased under drought stresses, but not at the same rate. Under control and drought conditions, the water content in sheaths was higher than that in leaves. Interestingly, under severe drought stress in 2015, the leaf water content was higher than the sheath water content. The water distribution between leaves and sheaths might be a response of plants to protect leaf system from devastation by drought. Proline was highly accumulated under drought stress but rapidly decreased after re-watering. The drought tolerant variety DA8 expressed higher ability in accumulation of proline than susceptible varieties. In general, total soluble sugar and starch contents in leaves and sheaths of varieties decreased under drought stress conditions. Total soluble sugar and starch content of DA8 were less affected than other varieties under drought conditions. Our study indicated that metabolisms of total soluble sugar and starch in rice were affected by both environmental conditions and characteristics of varieties. Proline accumulation ability of varieties can be used as a useful indicator for drought tolerant potential in rice breeding for water-limited environments. 相似文献
4.
PEG模拟干旱胁迫下甘蓝型油菜的根系特性与抗旱性 总被引：4，自引：0，他引：4
采用砂培法,利用14%（m/V）聚乙二醇（PEG-6000）模拟干旱胁迫,研究39份甘蓝型油菜发芽期根系性状的变化及其与抗旱性的关系。结果表明,干旱胁迫对油菜根鲜重和侧根数有明显的抑制作用,而对根长和根冠比的影响较小。相关分析表明,相对侧根数与活力指数之间以及根长与活力指数之间均呈显著正相关,可作为抗旱性鉴定的辅助指标。杂交种和常规种在根系性状上差别不显著,表明其抗旱能力相当。对油菜的抗旱性进行综合评价和聚类分析发现,在欧式距离为60时39份材料可分为5个类群,其中A类抗旱性最强,平均相对侧根数77.9%,相对根长98.9%;E类抗旱性最差,平均相对侧根数69.3%,相对根长84.5%。筛选出发芽期抗旱性较强的3份材料：OR918、OR805和OR2025。
相似文献
5.
Development of a standard evaluation protocol has been a pressing problem for the selection of drought‐resistant genotypes of tall fescue (Festuca arundinacea). This study was conducted to evaluate the association of forage yield with specific phenological and morphological traits to find a proper model for indirect selection under irrigated (normal) and drought‐stress conditions in tall fescue. A random sample of seventy‐five genotypes were clonally propagated and evaluated in normal and drought‐stress environments in the field during 2009 and 2010. Results showed that water stress had a negative effect on forage yield and most of the morphological traits measured and reduced genotypic variation for most of them. Forage yield had the highest genotypic variation, whereas days to pollination had the lowest variation. Low broad‐sense heritability estimates were obtained for dry‐matter yield, but heritability for the traits of number of stems per plant, plant height and crown diameter was moderately high. These traits were identified as the main components of forage yield. The importance of these components and their direct and indirect effects on forage yield was different in normal and drought‐stress conditions. This suggests that indirect selection for developing high‐yielding, drought‐tolerant varieties should be performed under drought‐stress conditions with a specific model. 相似文献
6.
施氮量和氮肥运筹模式对甘蔗前期生长的影响 总被引：4，自引：0，他引：4
以甘蔗品种ROC25、ROC22和台糖98/0432为供试材料,采取桶栽方法,通过对萌芽率、分蘖率和生长前期的株高及干物质积累量的调查,探讨不同施氮量和不同氮肥运筹模式对甘蔗前期生长的影响.结果表明:不同的甘蔗基因型对氮肥的敏感程度不一样,特早熟品种ROC25 在施N 225 kg/h㎡条件下分蘖率和干物质的积累量最高,施N 150kg/h㎡时6-7月份的株高最高;中熟品种ROC22在施N 225kg/h㎡的条件下前期各项农艺指标均为最优;中晚熟品种台糖98/0432施N 150 kg/h㎡最有利于分蘖,施N 225kg/h㎡条件下6-7月份的株高最高;1次施肥不利于甘蔗的萌芽和分蘖,但可促进甘蔗前期有机物的生成;2次施肥能促进甘蔗分蘖;3次施肥对甘蔗中后期的快速生长有重要的作用. 相似文献
7.
减氮对不同氮效率小麦品种花后光合物质生产力和产量的影响 总被引：3，自引：0，他引：3
为明确不同氮效率小麦品种对减氮的响应特点,以前期筛选出的氮高效品种扬麦25、宁麦21和氮低效品种扬麦22、扬麦20为材料,研究减氮模式对产量、氮肥利用效率、光合生产能力和干物质积累量的影响。结果表明,氮高效品种扬麦25和宁麦21的籽粒产量和氮肥利用效率显著高于氮低效品种扬麦22和扬麦20,氮高效品种的平均籽粒产量和平均氮肥利用效率较氮低效品种分别高10.9%和23.9%。与常规施氮处理(CK)模式相比,减氮20%并采用基肥和拔节肥各施氮90 kg·hm~(-2)(M4)模式下,氮高效品种开花期LAI、旗叶SPAD值、净光合速率及乳熟期旗叶SPAD值和净光合速率均未显著降低,且乳熟期平均LAI提高16.0%,进而使花后干物质积累量增加,从而实现产量稳定和氮肥利用效率的提高;而氮低效品种花后光合生产能力、籽粒产量和氮肥利用效率随施氮量降低而出现不同程度的降低。这说明,氮高效品种较氮低效品种有着更多的减氮潜力,前者在适量减氮和合理施肥方式下,可通过延缓花后叶面积衰减、保持较强的花后光合能力和增加花后物质生产力,实现产量稳定和氮肥利用效率提高。 相似文献
8.
Drought and heat are major abiotic stresses that significantly reduce crop yield and seed quality. In this study, we examined the impact of heat, drought and combined effect of heat and drought stress imposed during the grain filling stage in 18 US spring barley varieties. These impacts were assessed based on dry biomass, seed yield and six important malting quality traits, namely, beta-glucan, free amino nitrogen, soluble protein, refractive index, diastatic power and alpha-amylase activity. Singly applied heat or drought stress evoked a diverse set of responses among these varieties with respect to biomass, seed yield and malt quality traits suggesting these varieties can be exploited for enhancing barley production based on local conditions. Majority of the tested varieties performed poorly with reference to seed yield when the stresses were applied in combination, suggesting a lack of genetic diversity in the currently grown spring barley varieties to overcome co-occurring episodic drought and heat regimes, especially during heading stages. In the wake of global climate change, enhancing adaptive capacity of barley varieties by introducing novel germplasm into breeding programs or via new technologies is vital to sustain US barley production and meet the demands of the rapidly growing brewing industry. 相似文献
9.
水氮管理对不同氮效率水稻根系性状、氮素吸收利用及产量的影响 总被引：2，自引：1，他引：1
【目的】探究水氮管理措施对不同氮效率水稻根系构型、氮素吸收利用和产量形成的影响,以及根系性状特征与氮素吸收利用和产量关系。【方法】试验采用三因素裂裂区设计,主区为2个不同氮效率水稻品种德香4103(氮高效型)和宜香3724(氮低效型),裂区设置"常规灌溉"和"控制性交替灌溉"2种水分管理方式,裂裂区为SPAD指导施肥、优化施肥以及农民习惯施肥3种施氮模式,运用岭回归分析方法探究根系构型与氮素吸收利用和产量的关系。【结果】水稻抽穗期根系性状、产量、每穗粒数、千粒重及总颖花量均存在显著的基因型差异。氮高效品种德香4103每穗粒数多,群体库容量大,产量较氮低效品种宜香3724高0.24%~11.31%;控制性交替灌溉有利于水稻千粒重的增长,常规灌溉则对水稻有效穗数、每穗粒数及群体颖花量提高更为有利;SPAD指导施肥和优化施肥处理能够提高水稻有效穗数和每穗粒数,扩大群体颖花量以保证其对农民习惯施肥的产量优势;由于水氮互作效应的存在,控制性交替灌溉下施氮处理与空白处理水稻千粒重的差距比常规灌溉的大幅降低,使得控制性交替灌溉下施用氮肥的增产效果更佳。德香4103的氮肥生理利用率较宜香3724平均高8.69%,常规灌溉下水稻氮积累量较高,控制性交替灌溉下氮肥回收率、农学利用率、生理利用率均较优;与农民习惯施肥处理相比,SPAD指导施肥与优化施肥模式更有利于水稻氮素吸收利用效率的提高。拔节期、抽穗期和成熟期水稻根系构型与产量岭回归方程的决定系数范围为0.4198~0.9028,其中,抽穗期根系性状与产量关系最为密切,氮高效和氮低效品种的决定系数均超过0.9。在拔节期,水稻细分枝根长对产量影响最大;在抽穗期,氮高效和氮低效品种存在差异,前者是粗分枝根长,后者是细分枝根表面积对产量影响最大;在成熟期,不定根长与产量关系最为密切。水稻抽穗期根系构型对氮积累量变化的解释程度较高,岭回归方程决定系数均接近0.7。就水氮管理措施而言,氮高效和氮低效水稻均应采用常规灌溉配套SPAD指导施肥或控制性交替灌溉结合优化施肥来实现产量的提高。【结论】水稻抽穗期根系构型与产量、氮积累量关系密切,采用合理的水氮管理措施能够实现水稻产量和氮素吸收利用效率的同步提高。 相似文献
10.
《Journal of Crop Improvement》2013,27(2):175-211
Summary Nitrogen use efficiency (NUE) is defined as dry matter yield produced per unit of N supplied and available in the soil. NUE is approximately 33% for cereal production worldwide. Increased cereal NUE must accompany increased yield needed to feed the growing world population. Consequently, continued efforts are needed to include plant selection under low N input which is not often considered a priority by plant breeders. Molecular markers have accelerated plant breeding in a number of areas including biotic (disease and insect) resistance and abiotic (drought, low nitrogen fertilization and frost) tolerance. Marker-based technology has already provided scientists with a powerful approach for identifying and mapping quantitative trait loci (QTL) and would lead to the development of a better understanding of genetic phenomena. Two main NUE studies have been discussed. The first study identified QTL for NUE in maize involved the grain yield and secondary morphological traits of interest, such as plant height, ear leaf area, ears per plant and kernels per ear. This was compared with second study of QTL for yield and its components with genes encoding cytolistic gult-amine synthestase and leaf N03 - content. These secondary traits were correlated with yield and demonstrated segregation with high heritability under low nitrogen conditions. Marker assisted selection (MAS) should be able to offer significant advantages in cases where phenotypic screening is particularly expensive or difficult, including breeding projects involving multiple genes, recessive genes, late expression of the trait of interest, seasonal considerations, or geographical considerations. In addition to reducing costs of conventional breeding, MAS also has the potential to generate time savings. Possibly, the greatest contribution of QTL mapping to plant breeding will be the basic understanding of the genetic architecture of quantitative traits, thereby relating specific genetic loci with the biological mechanisms associated with desirable phenotypes. 相似文献
11.
为了探究盐旱交叉胁迫对花生生长发育的影响,以抗旱不耐盐花生品种花育22和抗旱耐盐花生品种花育25为试验材料,通过防雨棚盆栽试验研究了干旱、盐、盐+干旱、干旱后复水+盐等4种胁迫对花生产量、农艺性状、生物量、叶绿素SPAD值、丙二醛含量、活性氧清除能力及渗透调节物质含量的影响。结果显示：各胁迫处理均显著抑制了两个花生品种植株的生长和荚果产量,其中,盐胁迫对花育22生长的影响大于干旱胁迫;盐+旱胁迫下,两个花生品种受伤害程度最大,产量最低。与单一盐胁迫相比,干旱预处理提高了盐胁迫后期花生超氧化物歧化酶和抗坏血酸过氧化物酶活性,增强了植株活性氧清除能力,降低了叶片丙二醛含量,从而缓解盐胁迫对膜系统的过氧化伤害,提高了叶绿素含量,促进了植株生长,增加了干物质积累,最终提高盐胁迫下花生产量。另外,与单一盐或干旱胁迫相比,盐+旱胁迫对花育22和花育25的伤害均加重,而干旱预处理有利于2个品种在盐胁迫下活性氧代谢和光合色素的提高,促进植株的生长,提高植株对盐胁迫的交叉适应能力,从而缓解盐胁迫对花生植株的抑制作用。 相似文献
12.
甘蓝型油菜种质氮素营养效率的鉴定及评价指标筛选 总被引：1，自引：0，他引：1
为建立甘蓝型油菜种质氮素营养效率的鉴定及评价方法,筛选合理的次级评价指标和氮素营养高效基因型,在田间小区试验条件下设置低氮(45 kg/hm2)、中氮(180 kg/hm2)和高氮(270 kg/hm2) 3个施氮水平,测定了416份不同生态类型甘蓝型油菜种质植株性状及氮素吸收效率(NAE)、氮素利用效率(NUE)和氮收获指数(NHI)。各性状在不同氮素水平下对氮的敏感性不同,低氮下第一次有效分枝数的变异程度表现为最大,单株籽粒重次之;中氮和高氮处理水平下单株籽粒重的变异程度均表现为最大,低氮胁迫加大了种质间的差异。油菜种质氮素营养效率基因型间差异明显,表现中效类型的种质最多,高效和低效的较少。油菜种质间成熟期NAE的鉴定与评价应选择在低氮处理下,以单株籽粒重、单株地上干重和株高为间接指标进行选择效果明显;油菜种质间成熟期NUE的鉴定与评价应选择在高氮处理下,以单株地上干重、第一次有效分枝数、单株籽粒重和每角粒数为间接指标进行选择效果明显;油菜种质间成熟期NHI的鉴定与评价应选择在低氮处理下,以单株籽粒重、单株地上干重和茎基粗为间接指标进行选择效果明显。 相似文献
13.
PEG胁迫下甘蓝型油菜品种（系）种子发芽耐旱性鉴定 总被引：10，自引：2，他引：8
以10%（w/v）PEG6000做渗透介质模拟干旱条件,对不同来源的甘蓝型油菜(Brassica napus L.)品种（系）进行干旱胁迫下种子发芽鉴定,分析油菜种子发芽耐旱性的遗传多样性。结果表明：干旱胁迫下,部分材料处理与对照的发芽性状有显著性差异,81个甘蓝型油菜材料的平均苗高处理比对照低36.5％,平均鲜重处理比对照低31％,成苗率降低11.1％。甘蓝型油菜品种（系）耐旱性有较大遗传差异,幼苗活力指数的变异幅度为19％－81%,平均活力指数为55％。相关分析表明,活力指数与胁迫下的发芽性状达极显著正相关,可以作为油菜种子发芽耐旱的综合指标。根据活力指数,将81个油菜资源划分为强,中,弱三个耐旱等级,并筛选到30295,30253,中双6号,30703,30296,30290,30704,中油杂9号,德油4号等一批耐旱遗传资源。 相似文献
14.
为筛选抗旱品种提供依据,本试验从14份红花品种中筛选出2个抗旱品种（PI401470和PI401477 ）和2个干旱敏感型品种（系）（PI560169和川红1号）,并以此4份品种（系）为材料,研究干旱胁迫对红花幼苗光合、渗透调节物质和抗氧化物保护酶等生理生化特性的影响。结果表明,干旱胁迫下,4个红花品种（系）叶片净光合速率（Pn）、气孔导度（Gs）、胞间CO2浓度（Ci）和蒸腾速率（Tr）均呈不同程度的下降趋势,且品种间差异显著（P﹤0.05）;抗旱红花品（系）的各光合特性指标降幅均低于敏感型红花品种（系）。干旱胁迫条件下,渗透调节物质可溶性糖、可溶性蛋白质、脯氨酸含量均上升,保护性酶SOD、POD和CAT活性也均呈升高趋势,且抗旱型红花品种（系）的增长率高于敏感型品种（系）;抗旱型品种（系）MDA含量增长率低于敏感型品种。对11项指标进行主成分分析,提取了2个主成分,以净光合速率、气孔导度、胞间CO2 浓度、蒸腾速率、SOD活性和CAT活性为第一主成分,以可溶性蛋白质和脯氨酸为第二主成分的抗旱性鉴定指标,累计贡献率达89.50％。 相似文献
15.
《Plant Production Science》2013,16(3):155-159
SummaryA greenhouse experiment was conducted to compare root system development of two upland rice cultivars, IRAT 13 and Senshou, during recovery from drought stress and to identify the plant traits that confer drought resistance. From 62 days after sowing (62 DAS), drought stress was given for 6 d followed by rewatering for 14 d. Root length density (RLD) and root diameter (thickness) were measured at the end of the stress and rewatering periods. Control plants were well-watered throughout the study. Gultivar IRAT 13 had thicker roots and higher relative RLD (ratio of RLD in drought-stressed plants to that in control plants) than under drought stress, and significantly higher root growth recovery after rewatering cultivar Senshou. Related plant traits such as evapotranspiration (ET), leaf and stem dry weights and weight of senescent leaves (dead leaves) in IRAT 13 were significantly more favorable for drought resistance compared to Senshou. 相似文献
16.
不同小麦品种产量和氮素吸收利用的差异 总被引：4，自引：0，他引：4
为明确不同氮肥水平下不同小麦品种产量、氮素吸收和利用的差异,在大田条件下,以山东省主推的21个小麦品种为材料,研究了0、120、180、240和300kg·hm~(-2)共5个氮肥水平下不同小麦品种的产量、氮素利用率、氮素吸收效率和氮素利用效率等指标。结果表明,氮肥、品种及两者的互作效应显著影响冬小麦籽粒产量、氮素利用率、氮素吸收效率和利用效率;氮肥水平不同则品种间的氮效率差异程度不同。大部分供试品种的氮效率类型在不同氮肥水平下的聚类结果不一致,仅临麦4号、鲁原502、泰山28和山农25在各氮肥水平下的产量、氮素利用率均较高,可划为氮高效品种。氮高效品种达到高氮效率的途径不同,临麦4号通过高氮素吸收效率、泰山28通过高氮素利用效率、鲁原502和山农25通过氮素吸收效率和利用效率共同作用实现氮高效。由此可知,应在不同氮肥水平下对冬小麦品种进行产量和氮素利用率的综合评价,以筛选出适应不同地力环境的品种和与品种特性相适应的施肥技术;在氮高效品种的选育和推广中,应针对不同小麦品种的氮素吸收和利用特性进行鉴别和调控,才能最大程度挖掘和利用其高产、高效潜力,实现增产增效。 相似文献
17.
《中国油料作物学报(英文)》2020,5(3):114-120
To establish identification and evaluation methods of N (nitrogen) absorption and utilization of rapeseed (Brassica napus L.), difference of N nutrition efficiency (NNE) among rapeseed germplasms and relationship between NNE and plant traits under various N application rates were analyzed in this research. Pot cultivating experiments were conducted to investigate NNE with 3 N application rates in soil (0.05, 0.2 and 0.3 g/kg). A total of 12 rapeseed germplasms were planted, nitrogen absorption efficiency (NAE) and nitrogen utilization efficiency (NUE) in seedling stage, bolting stage, initial flowering stage, final flowering stage, and maturity stage were obtained. Results showed that bolting stage was the best period for NAE identification and evaluation. Low N application rate in soil (0.05 g/kg) was the best for NAE, and the indirect indexes were basal stem diameter, plant root dry weight and above ground plant dry weight. Maturity stage was the best period for NUE identification and evaluation. High N application rate in soil (0.3 g/kg) was the best for NUE, and indirect indexes were above ground plant dry weight and basal stem diameter. N application rates of 0.05 g/kg in soil was the best for nitrogen harvest index at maturity stage, and indirect indexes was number of pods per plant. Plant traits of rapeseed germplasms affected NNE. Higher basal stem diameter, plant root dry weight and above ground plant dry weight at bolting stage under low N application rate were important characteristics of N absorption in rapeseed. Higher above ground plant dry weight and basal stem diameter at maturity stage under high N application rate were important characteristics of N utilization. Higher number of pods per plant at maturity stage under lowe N application rate was an important characteristic of N harvest index. These results provided a reliable index for N management and provided theoretical basis for guiding rapeseed breeding. 相似文献
18.
Influence of drought stress on Mexican rice borer (Lepidoptera: Crambidae) oviposition preference in sugarcane 总被引：1，自引：0，他引：1
Two sugarcane, Saccharum hybrids, varieties were grown in the greenhouse under well watered or drought conditions to examine the influences of stress on Mexican rice borer, Eoreuma loftini (Dyar), oviposition preference and selected nutritional components without impinging factors common to field conditions that alter responses. Our research revealed that, under controlled conditions, drought induced a wider range and greater uniformity of free amino acid (FAA) accumulations than have been previously reported. Drought stress resulted in increased dry leaf tissue and elevated concentrations of 7 of 9 detectable free essential (for insect health) amino acids in stalks, the chief food of Mexican rice borer larvae. Stressed sugarcane was preferred for oviposition, likely related to greater numbers of dry leaves and heightened host plant nutritional quality. Dry leaf tissue, which is not consumed, may be a cue for improving chances of larvae encountering nutrient-enhanced living tissue, and for concealing eggs in folds. Excised dry leaf tissue from the treatments was indistinguishable for oviposition preference; therefore, biochemical status of living tissue may provide oviposition cues. Varieties exhibited no major genotypic differences in FAA accumulations or oviposition preference. 相似文献
19.
R. Venuprasad S.M. ImpaR.P. Veeresh Gowda G.N. AtlinR. Serraj 《Field Crops Research》2011,123(1):38-46
The development of near-isogenic-lines (NILs) is a very important tool for both genetic and physiological dissection of drought resistance in rice. Two pairs of NILs differing for grain yield under drought stress were isolated and characterized for yield, yield related traits, and several physiological traits in a range of contrasting environments. In replicated field trials both NIL pairs differed significantly for grain yield under drought stress but showed similar yield potential, phenology, and yield component traits under non-stress conditions. A polymorphism analysis study with 491 SSRs revealed that both NIL pairs are at least 96% genetically similar. These NILs show that small genetic differences can cause large difference in grain yield under drought stress in rice. In both pairs the drought-tolerant NILs showed a significantly higher assimilation rate at later stages both under stress and non-stress conditions. They also had a higher transpiration rate under non-stress condition. The most tolerant NIL (IR77298-14-1-2-B-10) had significantly higher transpiration rate and stomatal conductance in severe stress conditions. In one pair the tolerant NIL had constitutively deeper roots than the susceptible NIL. In the second pair, which had higher mean root length than the first pair, the tolerant NIL had more roots, greater root thickness, and greater root dry weight than the susceptible NIL. Deeper root length may allow tolerant NILs to extract more water at deeper soil layers. It is concluded that enhanced rooting depth is an important strategy for dehydration avoidance and rice adaptation to drought stress, but root architecture might not be the only mechanism causing the significant yield increase we observed in lowland drought stress environments. To further dissect the drought avoidance mechanisms in rice, analysis of root hydraulic properties may be necessary. 相似文献
20.
干旱胁迫对花生生长发育和光合产物积累的影响 总被引：4，自引：0，他引：4
采用人工控制条件下的防雨棚土柱栽培试验,以不同抗旱类型花生品种为材料,设置充分灌水和中度干旱胁迫处理,对苗期、花针期、结荚期、饱果期和成熟期(播种后30d、50d、75d、103d和132d)5个生育时期地上部不同器官和根系物质积累的影响进行了研究。结果表明,随生育期的进行,除花育22号在全生育期干旱胁迫条件下呈渐升趋势至成熟期最大外,花育23号和花育25号2品种根系干物质积累量均呈"抛物线型"变化趋势。干旱胁迫使花育23号根系干物质积累量峰值出现在结荚期,而花育25号峰值滞后到饱果期。3品种根重和荚果干物质积累量大小顺序均表现为:花育25号花育22号花育23号;通过Logistic方程能很好地拟合各品种地上部各器官、根系及植株生长发育情况。干旱胁迫使花育22号和花育23号两品种最大生长速率(Vm)明显降低,花育25号明显升高,但3品种地上部植株物质积累最大速率出现的时间(Tm)均明显滞后;地上部叶片和茎Vm降低,Tm延长;干旱胁迫使花生光合作用降低,光合产物积累缓慢,植株生长发育迟滞。3品种表现出对干旱胁迫适应性的差异,花育23号品种对水分较为敏感,抗旱性较差,花育25号具有较强的抗旱性。 相似文献