微生物多糖对草地早熟禾抗旱胁迫生理指标的影响

[目的]探讨3种微生物多糖对草地早熟禾抗旱胁迫生理指标的影响。[方法]采用微生物多糖均匀喷施草坪草,根据高渗溶液胁迫法,喷施20%聚乙二醇(PEG6000)1 g/株,干旱胁迫7 d后,测定相关生理指标。[结果]酵母多糖J总体抗旱效果最佳,相对电导率分别比CK低25.31%、光合色素含量比CK高25.81%和生物学积累地上部分和地下部分比CK高11.86%和16.69%。细菌多糖X和真菌多糖作用效果类似,而真菌多糖D处理的草坪草叶片中丙二醛含量最低,比CK低53.16%。[结论]为开发安全、绿色的微生物多糖制剂奠定了理论基础。

广西春大豆品种抗旱性评价及抗旱鉴定指标初步研究

【目的】评定13个广西春大豆品种的抗旱性,为广西春旱地区推广大豆新品种提供依据,并为利用简单高效的形态指标进行大豆抗旱性育种提供理论基础。【方法】采用盆栽干旱胁迫法,利用叶片萎蔫度、抗旱系数、隶属函数值指标对13个大豆品种的抗旱性进行综合评定。【结果】桂春8号、桂春10号、桂春11号叶片萎蔫度综合评定为Ⅰ级;桂春8号、桂春11号、桂春10号、桂春1号抗旱系数均大于0.70,其隶属函数均值也高于0.65。【结论】桂春8号、桂春11号、桂春10号和桂春1号均为高抗旱型品种,可在广西春旱地区推广种植,并可作为抗旱性品种资源应用于抗旱育种;选择与抗旱性密切相关的主要特征性状如单株粒数、单株粒重、单株荚果数、分枝数、株高、底荚高、主茎节数等,利用抗旱系数或隶属函数进行高抗旱型大豆品种选育是可行的。

滇重楼种质资源抗旱综合评价及生理机制研究

水分是限制滇重楼种子休眠萌发及资源分布的重要成因。以云南滇重楼主产区6个种源地的种子为试验材料,湿度设置分别为10%(正常水分处理,CK)和3%(水分胁迫处理,T),测定10、30和60 d时种子的可溶性蛋白(soluble protein,SP)、丙二醛(malondialdehyde,MDA)、过氧化氢酶(catalase,CAT)、过氧化物酶(peroxidase,POD)和超氧化物歧化酶(superoxide dismutase,SOD)的生理活性,对资源进行综合抗旱评价,并筛选抗旱生理指标。结果表明:随胁迫时间延长,滇重楼种子可溶性蛋白呈先下降后回升的趋势,而SOD和CAT酶活性呈先升高后降低的趋势,MDA和POD呈下降趋势。CAT活性对水分胁迫最为敏感,胁迫和对照间呈显著差异,60 d时呈极显著差异(P<0.01);在10 d时SOD和MDA对水分胁迫呈极显著响应(P<0.01),在30 d时各生理指标均受到显著影响,SOD和POD受到极显著影响(P<0.01)。相关性分析结果显示,可溶性蛋白与SOD和POD呈显著负相关(P<0.05)。滇重楼种质资源之间变异系数较大,不同种质材料对干旱胁迫的敏感性不同。综合分析,师宗、鹤庆和石林的滇重楼种源抗旱性较强,耿马地区抗旱性最弱,可为进一步抗旱基因型品种选育提供理论依据。不同评价方法对滇重楼抗旱生理指标筛选的结果较为一致,CAT、SOD和MDA可作为抗旱性鉴定的生理指标。

干旱胁迫和复水后台湾相思、银合欢和火棘幼苗的生理变化

以台湾相思、银合欢和火棘幼苗为试验材料,人工模拟干旱胁迫环境,通过测定各树种幼苗叶片的生理指标,研究了干旱胁迫对这3种幼苗的影响,并用主成分法综合评定了各树种的抗旱性。结果表明,干旱胁迫期间3种幼苗的叶片组织含水量下降,复水处理后恢复到与对照相近水平;3种幼苗叶片的叶绿素含量上升,复水后下降;3种幼苗叶片的脯氨酸、可溶性蛋白、可溶性糖含量上升或上升后下降,复水后一般恢复到对照水平;台湾相思和火棘幼苗的叶片SOD活性显著上升后小幅波动,而银合欢的幼苗叶片SOD活性持续增加;台湾相思和火棘幼苗的叶片丙二醛含量逐渐上升,银合欢上升后波动。3种幼苗叶片的SOD活性和丙二醛含量复水后均下降。对生理指标进行主成分分析表明,3种幼苗的抗旱性为台湾相思>银合欢>火棘。

微生物多糖对草地早熟禾抗旱酶系及生理生化指标的影响

[目的]探讨3种微生物多糖对草地早熟禾抗旱胁迫下抗性酶系及生理生化指标的影响。[方法]采用微生物多糖均匀喷施草坪草,根据高渗溶液胁迫法,喷施100 m L 20%聚乙二醇,干旱胁迫7天后,测定相关生理指标。[结果]酵母多糖J和细菌多糖X对抗性酶系和生理指标均有影响,酵母多糖J对POD活性、SOD活性、SS含量比CK高2.56、2.13和4.54倍,细菌多糖X对CAT活性、Pro含量、SP含量比CK高3.15、5.26和2.46倍,而真菌多糖D在降低MDA活性上效果最佳,比CK低53.6%。[结论]为开发安全、绿色的微生物多糖制剂奠定理论基础。

植物内生真菌次生代谢产物对草地早熟禾抗旱能力的影响

[目的]探讨3种植物内生真菌次生代谢产物对草地早熟禾抗旱胁迫下抗性酶系及生理生化指标的影响。[方法]均匀喷施植物内生真菌次生代谢产物1 d后,采用高渗溶液胁迫法,喷施100 mL 20%聚乙二醇,干旱胁迫7 d,测定相关生理指标。[结果]喷施代谢产物D后,相对含水量(RWC)比CK高10.7%,CAT和POD活性均为CK的1.98倍,细胞膜相对透性比CK低48.78%,MDA含量比CK低26.45%。喷施代谢产物S后,SOD活性是CK的2.01倍,SS含量是CK的3.72倍,SP含量比CK高23.80%。喷施代谢产物对叶绿素含量影响不显著。[结论]为开发安全、绿色的微生物制剂奠定理论基础。

裸子植物形态解剖结构特征与抗旱性研究进展

对裸子植物的叶、茎、根等营养器官在水分胁迫下的形态及解剖特征响应等方面的研究成果进行全面阐述,并探讨裸子植物的形态特征表现与其抗旱机理间的关系。研究结果可为裸子植物的抗旱资源选育,特别是早期形态诊断,以及资源保护提供参考。

西藏试种9份印度芥菜型油菜的抗旱性评价

为西藏芥菜型油菜抗旱性育种提供更多的种质资源,本研究试种了引自印度的9份芥菜型油菜,并对其进行了抗旱性评价。结果表明:干旱胁迫下,通过对9份印度芥菜型油菜叶片抗旱性数据与对照品种叶片数据的对比分析,综合分析出三个抗旱性比较强的品种:JM018、JO009、Kranti。

Effects of Drought Stress and Re-watering on Growth and Yield of Different Maize Varieties at Tasseling Stage

[Objective] The aim was to explore the response of different maize vari- eties in Guangxi to drought stress and re-watering at tasseling stage, so as to pro- vide reference for study on drought resistance mechanism, breeding of drought-re- sistant varieties and selection of maize varieties for fall sowing. [Method] At the tasseling stage, total five degrees of drought stress （4, 8, 12, 16 and 20 d） and corresponding re-watering after drought stress were simulated by a tub planting ex- periment in greenhouse for five different maize varieties （Guidan 0810, Dika 008, Zhengda 619, Chenyu 969, Guidan 901）. Normal watering was set as the control. Sampling was carried out on Day 1 after drought stress and on Day 15 after re- watering, and the secondary root number, maximum root length, green leaf number, root dry weight and shoot dry weight were measured. At the harvest time, the ear yield per plant was measured. With yield as the basis, the drought resistance coef- ficient and drought resistance index were calculated. Cluster analysis was conducted for drought resistance coefficient. [Result] The shoot dry weight, root dry weight, secondary root number, maximum root length and green leaf number of maize in the treatment groups decreased compared with those in the control group. The ratio of each index between the treatment and control groups declined with the extension of drought stress. After re-watering, the re-growth amount of each index all de- creased as the stress time prolonged. Post-re-watering over compensation effect oc- curred in none of the indices except the maximum root length, after 4 days of drought stress. Under drought stress, the reductions of all the indices of Guidan 0810, Dika 008 and Zhengda 619 were smaller than those of Chenyu 969 and Guidan 901. After re-watering, the re-growth abilities of Guidan 0810, Dika 008 and Zhengda 619 were stronger than those of Chenyu 969 and Guidan 901. The drought resistance coefficients and drought resistance indexes of Guidan 0810, Dika 008 and Zhengda 619 were all greater than those of Chenyu 969 and Guidan 901. The results of drought resistance coefficient cluster analysis showed that the five maize varieties were classified into two groups： Guidan 0810, Dika 008 and Zheng- da 619 had strong drought resistance, while Guidan 901 and Chenyu 969 had weak drought resistance. [Conclusion] The root and shoot growth of Guidan 0810, Dika 008 and Zhengda 619 was slightly affected by drought stress during the tasseling period, and they restored the growth rapidly after re-watering, thus ensuring high biomass and yield. Therefore, Guidan 0810, Dika 008 and Zhengda 619 can be promoted as drought-resistant autumn maize varieties in Guangxi.

Study on Change Laws of Cold Tolerance in Wheat under Drought Stress

In order to study the change laws of cold tolerance in wheat under drought stress, 11 wheat varieties planted in Huang-Huai wheat area and one variety representative in middle-lower Yangtze River wheat area were selected, and the their change laws of cold tolerance under normal moisture condition and drought stress condition. The results showed that under drought condition, the cold tolerance of wheat in various growth stages was remarkably lower than that under nondrought condition, and the decreasing amplitudes were the largest in overwintering stage with an average of 4.91 ℃, the smallest in regreening stage, and in the middle in the jointing stage. Under non-drought condition, the cold tolerance of semi- winter varieties in various growth stages was better than that of spring varieties, there were significant differences between different varieties, and the cold tolerance of all varieties in overwintering stage was improved compared with before winter, and rapidly decreased after overwintering. Semiwinter varieties showed cold tolerance remarkably enhanced in overwintering stage, and the cold tolerance of spring varieties was also improved to a certain degree.

Effects of Drought Stress on Antioxidant System of Leaves from Different Citrus Rootstocks

[Objective] The paper aims to study the effects of drought stress on antioxidation system of different Citrus rootstock leaves. [Method] Potted plant experiments were carried out to control the water content of soil in pots,in order to investigate the effects of drought stress on antioxidation system activity （SOD,POD and CAT） and the content of protein,GSH,MDA and O-·2 from the leaves of Shandong Zhike,Ningminju,Yangshuojinbaosuanju,Huapijinju and Guizhi No.1. [Result] The content of chlorophyll a,chlorophyll b and chlorophyll （a＋b） from the test 5 breeds decreased with the enhancement of drought stress,and there were significant differences between them and the control under the severe stress; the activities of SOD,POD and CAT from the 5 breeds increased as the drought stress strengthened; the content of soluble protein declined while that of GSH,MDA and O-·2 rose because of the drought stress. [Conclusion] This research provided a good reference to choose the breeds of citrus rootstocks in arid and semi-arid areas.

Anatomy of Different Ages of Streblus asper Leaves and Their Drought Resistance

The leaf thickness, stratum corneum thickness, epidermis thickness, palisade tissue thickness and sponge tissue thickness of Streblus asper leaves at different ages were observed by using paraffin section technology and optical microscopic observation to explore the anatomic adaptive response mechanism to drought stress, also to provide a theoretical basis for S. asper introduction. The results showed that under drought stress, various parts of S. asper leaf anatomy showed some characteristics adapted to water environment. Leaf palisade tissue cells became shorter, increasing from 1-2 layers to 2-3 layers; sponge cells were arranged in neat and compact long column shape, and the upper and down epidermis were thickened. The upper and down epidermis produced more trichomes to resist stress. After rehydration, leaf porosity increased and trichomes had a corresponding reduction. The principal component analysis showed that the stratum corneum thickness, leaf thickness and palisade were available to describe the impact of stress and rehydration on different ages of S. asper leaf anatomy. Under drought stress, S. asper leaf stratum corneum thickness and leaf thickness increased and leaves returned to normal after rehydration. Middle and top leaves were better than basal leaves in response to drought stress sensitivity.

Physiological Response of Paspalum notatum’s Leaf and Root under Persistent Drought Stress

To investigate the correlation and difference between Paspalum notatum’s leaf and root under drought adversity,this study tested the physiological responses of wild Paspalum notatum’s leaf and root under 0(CK),1,3,5,7,14,21,and 28 d drought stress treatment.These physiological responses include osmotic regulating substance,antioxidant enzyme activity,malonaldehyde content,cell membrane permeability,and chlorophyll content.According to the results,the soluble protein content,proline concentration,malonaldehyde content,cell membrane permeability and CAT activity in Paspalum notatum’s leaf and root tended to increase with the prolongation of drought stress;the soluble sugar content and SOD activity first increased and then decreased;POD dropped gradually;the contents of chlorophyll a,b and total chlorophyll first declined,then mounted,and lastly dropped again.During the early stage of drought stress,SOD and CAT acted as the main antioxidant enzymes in Paspalum notatum’s leaf and root.However,with the aggravation of drought stress the predominant antioxidant enzymes became SOD in the root system whereas CAT and POD in the leaf.It implicates drought has a strong influence on root’s CAT and leaf’s SOD and POD.Leaf is the major organ regulating the osmosis and photosynthesis of Paspalum notatum.The findings can provide a useful theoretical basis for improving Paspalum notatum’s drought tolerance.

Responses of antioxidant defense system of epilithic mosses to drought stress in karst rock desertified areas

Barbula fallax Hedw., Erythrodontium julaceum(Schwaegr.) Par., and Bryum argenteum Hedw. are typical rock mosses growing on rocks in different terrestrial habitats. In this study, B. fallax and E. julaceum, which are epilithic mosses growing in rock desertification in Guizhou, China, were used as ecophysiological mosses in a combination of field investigations and laboratory experiments. We also investigated the reference moss B. argenteum, which is a widely distributed moss in habitats with soil as substrate. Our research focused on the response of the antioxidant defense system of epilithic mosses to drought stress. Most antioxidant defense indicators increased initially, then declined at later stages of drought stress. In contrast, the carotenoid content increased constantly. In addition, there was an initial increase(albeit variable) in relative membrane permeability, with this parameter showing a parabolic trend in all of the epilithic mosses. Among the three species, E. julaceum demonstrated the strongest resistance followed by B. fallax and then by B. argenteum. The epilithic mosses displayed stronger resistance compared to the native mosses; the increase in O_2 content and other reactive oxygen species(ROS) at the early stage of drought stress induced the enzymatic and non-enzymatic scavenging systems tosequester ROS. Moreover, the radical scavenging ability and strong drought tolerance was maintained. The longterm growth of bryophyte under drought conditions in a karst environment can help eliminate the intense response of mosses to drought stress as they adapt.

苏铁耐旱、抗寒及光合生理特性研究

采用干旱胁迫及人工模拟冷冻试验 ,进行苏铁耐旱、抗寒及光合生理特性研究 ,结果表明 :不同年龄苏铁的耐旱性、抗寒性及光合生理指标存在明显差异 ,随苏铁叶龄增加 ,苏铁叶片水势、冻害敏感指数和 NR活力下降 ,蒸腾速率、自然饱和亏和叶绿素含量增加 ,苏铁耐旱及抗寒性增强 ;苏铁水分及光合生理指标对干旱胁迫反应敏感 ,随干旱胁迫加剧 ,苏铁叶片水势、蒸腾速率、叶绿素、NR活力及净光合速率下降 ,而自然饱和亏增大 ,以适应胁迫环境 ,使苏铁表现出较强的抗旱性和生命力。

绣球抗旱性综合评价及指标体系构建

采用盆栽持续干旱处理,测定5个耐旱能力不同的绣球品种生根苗25项生理生化指标,研究各品种绣球的抗旱性强弱,构建绣球品种抗旱性评价体系.结果表明:干旱胁迫20d后,绣球的比叶质量、细胞膜透性、丙二醛含量、超氧化物歧化酶活性、可溶性糖含量、脯氨酸含量、胞间CO_2浓度和非光化学猝灭系数均显著升高,而叶片相对含水量、净光合速率、气孔导度、蒸腾速率、光系统Ⅱ实际光量子产量和电子传递速率均显著降低.主成分分析将25项生理生化指标转化为3个互相独立的综合指标(累计贡献率达87.1%),主成分1主要反映光合、荧光等信息,主成分2主要反映植株活力等信息,主成分3主要反映膜系统及渗透调节系统等信息.聚类分析将5个绣球品种划分为3个类型:拉维布兰和塔贝为耐旱型品种,你我的浪漫为中间型品种,无尽夏新娘和银边为不耐旱型品种.根据绣球品种抗旱性综合评价值D,5个品种的抗旱性排序为拉维布兰>塔贝>你我的浪漫>无尽夏新娘>银边.细胞膜透性、过氧化物酶活性、可溶性蛋白含量和电子传递速率4个指标对绣球抗旱性有显著影响,可简化绣球抗旱性鉴定工作.

异位表达苹果G蛋白偶联受体基因MdGCR1降低烟草的抗旱性

以‘嘎拉’苹果(Malus×domestica‘Royal Gala’)为材料,采用同源克隆和PCR技术分离了G蛋白偶联受体基因MdGCR1。其开放阅读框(ORF)为960 bp,编码含有319个氨基酸的蛋白。系统进化树分析显示,MdGCR1与梨GCR1亲缘关系最近,同源性最高。基因表达分析显示MdGCR1主要在苹果根、茎和叶中表达,在花和果实中的表达量较低;MdGCR1受多种逆境胁迫诱导,参与多种激素响应。构建了MdGCR1植物过表达载体,并通过农杆菌介导的遗传转化获得了转MdGCR1烟草。转基因材料抗性试验结果显示:超量表达MdGCR1显著降低烟草对干旱胁迫的抗性,表明苹果G蛋白偶联受体基因MdGCR1在响应植物抗旱胁迫中发挥重要作用。

苹果细胞分裂素O–糖基转移酶基因MdZOG1的分离与功能鉴定

以‘嘎拉’苹果为材料,采用同源克隆和PCR技术分离了苹果细胞分裂素O–糖基转移酶基因MdZOG1。MdZOG1的开放阅读框(ORF)长度为762bp,编码含有253个氨基酸的蛋白。系统进化树分析显示,MdZOG1与PbZOG1亲缘关系最近。基因表达分析显示MdZOG1主要在苹果根和茎中表达,在花和果实中的表达量较低。通过农杆菌介导的遗传转化获得转MdZOG1拟南芥和烟草。干旱处理试验结果显示:超量表达MdZOG1显著提高拟南芥和烟草植株的抗旱能力,表明苹果细胞分裂素O–糖基转移酶在植物抗旱胁迫中发挥重要作用。