小麦与彭梯卡偃麦草杂种及其衍生后代的细胞遗传学研究──Ⅱ．来自小麦和彭梯卡（长穗）偃麦草及中间偃麦草杂种后代11个八倍体小偃麦的比较研究

利用染色体配对分析和酯酶及种子醇溶蛋白电泳分析研究了我国育成的１１个八倍体小偃麦,结果表明：（ａ）来源于小麦和中间偃麦草杂交后代的６个部分双二倍体中,中１和中２的偃麦草染色体组不同于中３、中４、中５和小偃７８８２９的偃麦草染色体组;（ｂ）来源于小麦和长穗偃麦草杂交后代的５个部分双二倍体中,小偃７８４的偃麦草染色体组不同于小偃６９３和小偃７６３１中的偃麦草染色体组,表明在长穗偃麦草中有两个互不相同又不同于小麦的染色体组Ｅ和Ｆ,而小偃７４３０和小偃６８中的偃麦草染色体组很可能是Ｅ和Ｆ染色体组的重组体;（ｃ）小偃７８４中的长穗偃麦草染色体组和中５及小偃７８８２９中的中间偃麦草染色体组基本相同,而中２的中间偃麦草染色体组不同于小偃６９３和小偃７６３１中的长穗偃麦草染色体组Ｆ,这意味着在长穗偃麦草和中间偃麦草中可能只有一个共同的染色体组Ｅ。部分双二倍体中酯酶及醇溶蛋白偃麦草染色体特征带的存在和发现,为这些染色体或其片段导入小麦后的鉴定提供了方便。     

两个不同基因型小麦光抑制特性的比较

比较了两个不同基因型小麦（Ｔｒｉｔｉｃｕｍ ａｅｓｔｉｖｕｍ Ｌ．）“京４１１”和“小偃５４”的原初光能转化效率、荧光猝灭参数和光合色素对强光胁迫的响应。在正常生长条件下“京４１１”的光合色素含量高于“小偃５４”;但在高光强下“京４１１”出现明显的光抑制,而“小偃５４”对高光强的适应上优于“京４１１”。“小偃５４”适应高光强的原因是它在高光强下能大幅度地提高叶黄素循环的调控因子抗坏血酸的浓度及紫黄     

八倍体小偃麦和普通小麦旗叶及叶鞘光合日变化比较研究

以温室大棚中栽培的普通小麦'中国春'(对照)及八倍体小偃麦'小偃7430'(染色体组为ABDE_1)、'小偃693'(染色体组为ABDF_1)为材料,采用TPS-1光合作用测定系统及FMS-2荧光仪测定了开花期旗叶和叶鞘的净光合速率、气孔导度和叶绿素荧光参数的日变化,以揭示普通小麦与八倍体小偃麦旗叶及其叶鞘的光合作用差异.结果表明:八倍体小偃麦与普通小麦'中国春'的旗叶和叶鞘光合作用均有午休现象,净光合速率于上午11:00左右出现高峰,午间下降,下午又呈现上升趋势,且'小偃693'叶片在上午时上升较快;气孔导度和荧光参数F_v/F_m、Fv/F_o、 Φ_(PS)Ⅱ、ETR的变化趋势与净光合速率相似,而NPQ的变化趋势则相反.各光合作用和叶绿素荧光参数在材料间表现为八倍体小偃麦高于普通小麦'中国春',器官间表现为旗叶高于相应叶鞘,而'小偃693'的叶鞘和'中国春'叶片的相似.研究发现,八倍体小偃麦旗叶和叶鞘的光合效率优于普通小麦'中国春';'小偃693'的光合效率因其较高的光反应活性表现得尤为突出,其叶鞘的光合能力也不容忽视.     

高产小麦品种茎秆的解剖和化学特性

小麦(Triticum aestivum L.)新品种"小偃81",是由抗病虫害小麦品种"小偃54"和高产小麦品种"8602"杂交筛选出的具有优良特性的后代.作者运用多种实验手段,研究了新品种茎秆组织结构以及木质素含量和分布的变化规律.结果表明:与母本"小偃54"和父本"8602"相比,"小偃81"的茎秆直径变小、横切面上维管束数目减少,而茎秆直径与壁厚比、横切面上机械组织比例却显著增大,单位面积上维管束数目增多.Klason法测定木质素结果显示:"小偃81"茎秆中木质素含量高于"小偃54"和"8602".经Maule和Wiesner的木质素显色反应,"小偃81"茎秆横切面染色明显加深.用H2O2/Hac弃除酚酸以后,新品种小麦的木质素自发荧光明显强于亲本.FTIR分析结果表明:"小偃8l"中所含的紫丁香基、愈创木酚基等木质素特征基团的吸收峰值也显著高于亲本.由此推断,新品种"小偃8l"的茎秆具有优良的组织结构和化学组成.     

高产小麦品种茎秆的解剖和化学特性

小麦(TriticumaestivumL.)新品种“小偃81”,是由抗病虫害小麦品种“小偃54”和高产小麦品种“8602”杂交筛选出的具有优良特性的后代。作者运用多种实验手段,研究了新品种茎秆组织结构以及木质素含量和分布的变化规律。结果表明:与母本“小偃54”和父本“8602”相比,“小偃81”的茎秆直径变小、横切面上维管束数目减少,而茎秆直径与壁厚比、横切面上机械组织比例却显著增大,单位面积上维管束数目增多。Klason法测定木质素结果显示:“小偃81”茎秆中木质素含量高于“小偃54”和“8602”。经Ma黮e和Wiesner的木质素显色反应,“小偃81”茎秆横切面染色明显加深。用H2O2/HAc弃除酚酸以后,新品种小麦的木质素自发荧光明显强于亲本。FTIR分析结果表明:“小偃81”中所含的紫丁香基、愈创木酚基等木质素特征基团的吸收峰值也显著高于亲本。由此推断,新品种“小偃81”的茎秆具有优良的组织结构和化学组成。     

水分胁迫下小麦叶片蛋白质、淀粉和纤维素合成的示踪研究

利用光合１４ＣＯ２示踪技术,在－０．８ＭＰａＰＥＧ处理下,对等基因型不同抗旱性ＫＴＣ８６２１、ＮＤ７５３２和本地抗旱品种陕合６号小麦进行比较,其叶组织细胞质膜相对透性增加２７％－３２％,合成蛋白质放射性下降６２％－７０％;合成淀粉放射性下降必３％－６９％;合成纤维素放射性下降５９％－７１％。其中高抗旱的ＫＴＣ８６２１１大分子合成下降幅度小于等基因型低抗旱的ＮＤ７５３２和陕合６号,表明该品种叶体内大分子合成受水分胁迫的影响较小。正常水分条件下等基因型两品种叶酶溶物放射性及在ＰＥＧ干旱处理下的下降幅度均相近。陕合６号叶醇溶物放射性远远小于前两品种．     

硬粒小麦、提莫菲维小麦与四倍体长穗偃麦草属间杂种的形态和细胞遗传学研究

首次获得硬粒小麦（Triticum durum Desf),提莫菲维小麦（T.timopheevi Zhuk)与四倍体长穗偃麦草（tetraploid Elytrigia elongata)的属间杂种,杂交当代结实率分别为5．29％和1．41％,杂种均表现为多年生,具很强的生活力,形态上呈双亲中间类型,杂种F1自交不育,用普通小麦,硬粒小麦回交,以硬粒小麦为母本的F1均获得交种子,杂种F1花粉母细胞减数分裂中期I染色体配以构型分别为：13．78I＋6．87II＋0．147III,9．10I＋9．11 II＋0．20III,F1形成的二价体主要是四倍体长穗偃麦草染色体之间配对所致,并推测四倍体长穗偃麦草具促进小麦部分同源染色体配对或抑制小麦ph基因作用的特殊遗传系统。     

一个小麦-中间偃麦草异代换系的形态学和细胞学鉴定

中间偃麦草含有丰富的优良基因,在小麦的遗传改良中具有重要利用价值。对从中间偃麦草与小麦品种烟农15杂种后代(BC2F4)中选育的小麦种质系山农0095进行形态学和细胞学鉴定,结果表明：山农0095株高78cm,穗长17．3cm,旗叶长36．3cm,旗叶宽3．03cm,茎杆粗壮,繁茂性好,既长又宽的旗叶、长圆锥型穗是其显著的形态学特征;其根尖细胞染色体数日为2n=42,花粉母细胞减数分裂中期Ⅰ(PMC M Ⅰ)染色体构型为2n=21Ⅱ;它与普通小麦的杂种FⅠPMC M Ⅰ绝大多数细胞出现2个单价体,没有观察到多价体,平均染色体构型为2n=20．08Ⅱ 1．84Ⅰ。以上结果表明,山农0095是一个小麦-中间偃麦草的双体异代换系。     

小麦×长穗偃麦草的受精和早期胚胎发育

用石蜡切片法,对小麦（Ｔｒｉｔｉｃｕｍａｅｓｔｉｖｕｍ）和长穗偃麦草（Ｅｌｙｔｒｉｇｉａｅｌｏｎｇａｔａ）杂交的受精和早期胚胎发育进行了观察。结果表明,长穗偃麦草花粉在小麦柱头上萌发良好,花粉管可顺利长入花柱和胚囊。观察的１７０个小麦子房中,１７６５％发生了双受精,产生了胚和胚乳;９４１％发生了单卵受精,只产生胚而无胚乳;４７１％发生了单极核受精,只产生胚乳而无胚;总受精率为３１７７％;成胚率为２７０６％。由于胚乳的缺乏或发育异常及败育,最终难以获得有生活力的种子。为小麦与长穗偃麦草远缘杂交提供了细胞胚胎学证据。     

抗旱性不同的小麦幼苗对水分和NaCl胁迫的反应

分别测定抗旱小麦的８１３９（Ｔｒｉｔｉｃｕｍ ａｅｓｔｉｖｕｍ Ｌ．ｃｖ．８１３９）和干旱敏感品种甘麦８号（Ｔ．ａｅｓｔｉｖｕｍ Ｌ．ｃｖ．Ｇａｎｍａｉ Ｎｏ．８）在２０％ＰＥＧ６０００和１．２％ＮａＣｌ胁迫下的生长、光合作用、蒸腾作用及抗氧化保护系统的变化。结果表明,抗旱小麦８１３９对ＰＥＧ６０００有较强的抗性,但对ＮａＣｌ胁迫的抗性较差。ＮａＣｌ胁迫下,两种小麦根的生长均受到严重抑制,而在ＰＥ     

水分胁迫下荔枝叶片过氧化物酶和IAA氧化酶活性的变化

以适应山地栽培的抗旱性较强的东刘1号和适应河边栽培的抗旱性较弱的陈紫2年生荔枝（Litchi chinensis Sonn.)实生苗为试验材料,研究了水分胁迫下叶片细胞胞质,与（细胞）壁以离子键结合和壁以共价键结合的过氧化的酶（POD）和IAA氧化酶活性的变化。结果表明：在叶片中POD主要是以与壁以离子键结合的POD存在,占总活性的51．15％－52．15％,其次是细胞胞质POD,占44．20％－44．74％,与壁以共价键结合的POD活性最低,仅占3．44％－3．65％。与POD不同,IAA氧化酶绝大多数存在于细胞胞质中,占总活性的88．93％－89．29％,其次是少量的与壁以离子键结合的IAA氧化酶,占7．32％－7．63％,与壁以共价键结合的IAA氧化酶活性最低,仅占3．39％－3．44％;2个品种间差异不明显。水分胁迫下,叶片细胞胞质以及与壁以离子键和壁以共价键结合的POD和IAA氧化酶（比）活性均上升,抗旱笥较强的品种上升的幅度均大于抗旱性较弱的品种。     

贵州特有植物美丽红山茶水分胁迫的生理响应

采用水分抗逆性指标主成分分析法,选择4年实生苗,测定和评价了连续30 d水涝和干旱胁迫的生理响应.结果表明：(1)水涝处理的叶片生长旺盛,光泽度和观赏性无明显变化,叶片相对含水量、MDA含量、SOD活性、POD活性、CAT活性的变化差异在5％以内,土壤含水量增加3．47％,细胞膜透性减少1．59％,短期水涝对美丽红山茶伤害不明显;(2)随着干旱时间延长,新叶卷缩、老叶脱落,土壤含水量、叶片相对含水量随时间呈负相关缓慢减少,细胞膜透性呈正相关缓慢增长,但复水10 d 后可恢复正常生长,无明显生理变化响应;(3)SOD活性和MDA含量分别增加了0．66％和5．31％,POD活性随干旱时间上下波动而增加6．47％, CAT活性随干旱时间延长而增加,20 d增加33．33％达最大值20．8 U??g-1??min-1.在抗性生理中,维持膜稳定性的叶片含水量、POD和CAT的变化对抗旱能力大小起主要作用.     

钼在桃树干旱胁迫响应中的作用解析

以毛桃(Amygdalus persica)实生苗为试材, 研究干旱胁迫下, 钼酸铵处理对钼辅因子硫化酶编码基因(LOS5/ABA3)表达量、脱落酸(ABA)含量及抗旱相关生理指标的影响。结果表明, 干旱胁迫下, 喷施不同浓度钼酸铵处理毛桃实生苗叶片, 其含水量及叶绿素和脯氨酸含量显著高于对照, 且以0.04%钼酸铵处理效果最好; 电解质渗漏率显著低于对照。干旱胁迫下, 与对照相比, 喷施0.04%钼酸铵的毛桃实生苗叶片中LOS5/ABA3表达量显著提高; ABA含量、水分利用效率和净光合速率均高于对照, 蒸腾速率低于对照, 且差异显著; 叶片抗氧化酶活性显著升高, MDA含量显著降低; 离体处理的叶片质量损失减缓, 且差异显著。研究表明毛桃实生苗在干旱胁迫下喷施钼酸铵可通过上调钼辅因子硫化酶编码基因的表达水平, 提高叶片中ABA和脯氨酸含量及抗氧化酶活性, 从而缓解干旱胁迫下的细胞膜氧化伤害, 降低叶片失水速率, 减轻干旱胁迫对毛桃实生苗的伤害。     

硅和干旱胁迫对水稻叶片光合特性和矿质养分吸收的影响

硅被认为是植物生长的有益元素,它能增强植物对非生物逆境和生物逆境胁迫的抗性。以抗旱性不同的一对水稻近等基因系w-14-和w-20为实验材料,采用盆栽实验,研究了干旱胁迫下硅处理对水稻生长性状、光合生理特性和矿质养分吸收的影响。结果表明,在正常水分条件下硅处理对水稻的生长及生理特性没有明显影响。干旱胁迫显著降低水稻植株的生长,叶绿素含量、叶绿素荧光参数Fv/Fm及Fv/F0值显著降低,光合作用受到明显抑制。加硅能提高干旱胁迫条件下水稻植株的生物量、水分利用效率、叶片叶绿素含量、净光合速率和蒸腾速率,而气孔导度和细胞间隙CO2浓度则下降。无论干旱与否,施硅后水稻的叶片硅含量均显著上升。两个水稻品系叶片的无机离子含量在干旱胁迫条件下均呈显著增加的趋势,而硅处理后材料w-14的叶片K+、Na+、Ca2+、Mg2+、Fe3+含量分别降低16.38%,24.50%,19.70%,21.52%,18.58%,w-20则分别降低11.64%,12.11%,16.06%,11.11%和19.15%,并使之回复到与对照更接近的水平。研究结果表明了硅提高水稻植株的抗旱性与光合作用的改善和矿质养分的调节有关。     

Superoxide dismutase and peroxidase activities in drought sensitive and resistant barley (Hordeum vulgare L.) varieties

The effects of water deficit on relative water content (RWC), on the activity superoxide dismutase (SOD) and peroxidase (POX) from leaves of two drought-resistant barley strains (Hordeum vulgare L.) varieties (TOKAK-157/37 and 56000/MISC-233) and one sensitive (ERGINEL-90) were studied. In 21 day old seedlings, drought stress was initiated by withholding water and lasted for 12 days. Activity of SOD increased by the effect of drought treatments in the leaves of drought-resistant varieties TOKAK-157/37 and 56000/MISC-233 as compared to sensitive variety ERGINEL-90. The drought treatment resulted in a 418 % and 59 % increase in SOD activity in resistant varieties at the end of the 12^th day of experimental period. However, an increase in activity of SOD was not accompanied by an increase in activity of POX in drought-resistant TOKAK-157/37 and 56000/MISC-233 except on the 6^th day of drought treatment in 56000/MISC-233. In drought-sensitive variety, ERGINEL-90, POX activity did not change throughout drought period.     

Suboptimal nitrogen status sensitizes the photosynthetic apparatus in willow leaves to long term but not short term water stress

The response to drought was compared for willow plants of optimal leaf nitrogen content (100 N) and those of 86% of this content (86 N). Gas exchange measurements revealed that the carboxylation efficiency (CE) of photosynthesis was more sensitive to drought than the photosynthetic capacity in both N regimes. Since the leaf content of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) was found to be much more resistant it is suggested that a decreased specific activity of Rubisco underlies the decreased CE. Although the rate of water consumption was the same for 86 N and 100 N plants the photosynthetic apparatus responded much more rapidly in the 86 N leaves. This increased sensitivity of 86 N leaves was not due to accelerated senescence as judged by comparison with parallel plants subjected to discontinued fertilization; the two categories of treatments resulted in the same loss of leaf nitrogen and Rubisco but drought induced a much more rapid photosynthetic depression. In contrast to the drought situation, 86 N and 100 N plants behaved similarly when compared under short term water stress. First, when single attached leaves were exposed to a sudden drop in air humidity the capacity of CO₂ uptake in both N regimes decreased about 20% over 10 min while the leaf water potential remained high. Second, in freely transpiring leaf discs cut from 86 N and 100 N leaves the same relationship between capacity of O₂ evolution and extent of dehydration was observed. The possible mechanisms underlying the increased susceptibility of 86 N leaves to drought is discussed; the water status of the roots not the leaves is suggested to be the determining factor.Abbreviations CE carboxylation efficiency - 100 N optimal nitrogen regime - 86 N suboptimal nitrogen regime with 86% of the optimal leaf nitrogen content, Rubisco ribulose-1,5-bisphosphate carboxylase/oxygenase     

干旱胁迫下不同抗旱性小麦叶片内源激素含量的变化与抗旱力强弱的关系

以抗旱性强的小麦品种昌乐5号和抗旱性弱的鲁麦5号的幼苗为材料,研究了随着干旱胁迫的加剧,小麦叶片相对含水量、气孔导度和内源激素水平的变化．结果表明,叶片的气孔导度和细胞激动素与脱落酸含量的比值（CTKs/ABA）呈较强的线性正相关关系而与叶片RWC的相关关系较弱,说明气孔导度受CTKs/ABA调控,而不是受叶片RWC的调控．在不同强度的干旱胁迫下我们可以利用CTKs/ABA的变化判断品种抗旱性大小：①抗旱力强的小麦品种叶片的平均CTKs/ABA值较高,而弱者较低,说明强者内源促进型激素含量相对较高,从而在干旱胁迫下保持较高的生活力．②抗旱力强的小麦品种叶片CTKs/ABA与干旱处理天数呈二次负相关关系,而弱者是线性负相关关系,说明强者具有较强的抗逆缓冲能力．③抗旱力强的小麦品种成熟叶（第二叶）CTKs／ABA下降快,新叶（第三叶）下降慢,而弱者反之,说明抗旱性强者可能存在着较强的从成熟叶向新叶的物质运输从而具有自我保护性调节机制．     

Leaf cuticular waxes and physiological parameters in alfalfa leaves as influenced by drought

Drought significantly constrains higher yield of alfalfa (Medicago sativa L.) in arid and semiarid areas all over the world. This study evaluated the responses of leaf cuticular wax constituents to drought treatment and their relations to gas-exchange indexes across six alfalfa cultivars widely grown in China. Water deficit was imposed by withholding water for 12 d during branching stage. Cuticular waxes on alfalfa leaves were dominated by primary alcohols (41.7?C54.2%), alkanes (13.2?C26.9%) and terpenes (17.5?C28.9%), with small amount of aldehydes (1.4?C3.4%) and unknown constituents (4.5?C18.4%). Compared to total wax contents, the wax constituents were more sensitive to drought treatment. Drought decreased the contents of primary alcohol and increased alkanes in all cultivars. Alkane homologs, C25, C27, and C29, were all negatively correlated with photosynthetic rate, transpiration rate, stomatal conductance, and leaf water potential. Under drought conditions, both stomatal and nonstomatal factors were involved in controlling water loss from alfalfa leaves. No direct relationship was observed between wax contents and drought resistance among alfalfa cultivars. An increase in alkane content might be more important in improving drought tolerance of alfalfa under water deficit, which might be used as an index for selecting and breeding drought resistant cultivars of alfalfa.     

Effects of Drought Stress on Key Enzymes of Carbon Metabolism,Photosynthetic Characteristics and Agronomic Traits of Soybean at the Flowering Stage under Different Soil Substrates

Soybean is an important legume food crop, and its seeds are rich in nutrients, providing humans and animals with edible oil and protein feed. However, soybean is sensitive to water requirements, and drought is an important factor limiting soybean yield and quality. This study used Heinong 84 (drought resistant variety) and Hefeng 46 (intermediate variety) as tested varieties planted in chernozem, albic, and black soils. The effects of drought stress on the activities of key enzymes in carbon metabolism and photosynthetic characteristics of soybean were studied during the flowering stage, most sensitive to water. (1) The activities of SS-1, 6PGDH, and G6PDH enzymes in soybean leaves first increased and then decreased under drought stress. The enzyme activity was the highest under moderate drought stress and weakest in the blank group. (2) Drought stress increased Phi2, PhiNO, and Fm in soybean leaves and reached the highest value under severe drought; with the increase in drought stress, PhiNPQ and Fv/Fm of soybean leaves gradually decreased, reaching the lowest under severe drought. (3) With the increase in drought stress, F₀ and Fs of soybean leaves showed a single peak curve, and the maximum was at moderate drought. (4) Correlation analysis showed that F₀ was greatly affected by varieties and soil types; Fs, F0, and Fm soil varieties had a great influence, and chlorophyll fluorescence parameters were affected differently under drought stress with different drought degrees. (5) Drought stress changed the agronomic traits and yield of soybean. With the increase of drought degree, plant height, node number of main stem, effective pod number, 100-seed weight and total yield decreased continuously. (6) Drought stress affected the dry matter accumulation of soybean. With the increase of drought degree, the dry matter accumulation gradually decreased. Among them, the leaf was most seriously affected by drought, and SD decreased by about 55% compared with CK. Under the condition of black soil, the dry matter accumulation of soybean was least affected by drought.     

马蔺叶片解剖结构特征与其抗旱性关系研究

通过温室模拟干旱胁迫试验,从中国北方不同生境生长的15份野生马蔺种质材料鉴定出3个不同抗旱性群体(强抗旱、中度抗旱和弱抗旱),从中选择具代表性的不同抗旱级别的4份马蔺种质,进行其叶片组织解剖结构特征的观察和比较,以进一步证实马蔺叶片解剖结构特征及其与抗旱性的关系。结果表明,各种质材料间叶片厚度、上下表皮细胞厚度、角质层厚度、气孔密度、栅栏组织厚度、海绵组织厚度、栅栏组织/海绵组织厚度、CTR值和SR值等结构参数指标均与马蔺种质材料抗旱性存在密切的关系。其中,强抗旱种质材料的叶片厚度、上下表皮细胞厚度和角质层厚度大,气孔密度大,栅栏组织和海绵组织较发达,叶片组织紧密度大、疏松度小,栅栏组织/海绵组织厚度比较高;弱抗旱种质材料的叶片厚度、上下表皮细胞厚度和角质层厚度小,气孔密度小,栅栏组织和海绵组织较薄,叶片组织紧密度小、疏松度大,栅栏组织/海绵组织厚度比较低。