高温和干旱胁迫对西红柿幼苗生长、养分含量及元素利用效率的影响

全球气候变化将增加未来高温与干旱的发生频率和强度,然而高温与干旱的交互作用对农作物生长、养分含量及其利用效率的影响还不甚清楚。因此,研究高温与干旱交互作用对农作物生理生态的影响将为准确评价农作物对未来极端气候条件的响应提供科学依据。选取全球第四大经济作物——西红柿为研究对象,在人工智能气候箱中模拟高温和干旱环境。共设置两个水分处理(正常浇水;干旱)与两个温度处理(常温-26℃/19℃(白天/夜间);高温-42℃/35℃(白天/夜间)(7d))。主要测定指标包括生物量以及生物量分配、比叶面积、养分含量(全氮、全磷)、光合元素利用效率(光合氮素利用效率、光合磷素利用效率)。研究表明,高温、干旱单独作用以及交互作用均显著降低了根、茎、叶生物量以及总生物量,并且高温干旱交互作用使总生物量降低最多。在生物量分配方面,高温单独作用显著降低了根质量分数以及根冠比,而干旱单独作用增加了根质量分数、茎质量分数以及根冠比,但降低了叶质量分数。在养分含量方面,高温单独作用导致叶片全氮、全磷含量显著降低、茎全磷含量显著增加、根全磷含量显著降低。干旱单独作用导致叶片、茎全磷含量显著降低、根全氮含量显著升高。高温与干旱交互作用对生物量分配及养分含量的影响与干旱胁迫单独作用类似。在光合元素利用效率方面,高温、干旱单独作用均降低了幼苗光合氮素利用效率、光合磷素利用效率,并且高温加剧了干旱对光合磷素利用效率的影响。因此,在未来气候变化情况下,高温与干旱交互作用可能会对农作物产生更大威胁。     

干旱对辣椒光合作用及相关生理特性的影响

采用盆栽实验研究了干旱对5个栽培种Capsicum annuum L.(CA),Capsicum baccatum L.(CB),Capsicum chinenseJacquin.(CC),Capsicum frutescens L.(CF)Capsicum pubescens Ruiz&Pavon(CP)和1个野生种Capsicum baccatum var.baccatum(CBY)的光合作用及相关生理特性的影响。结果发现,干旱条件下辣椒的光合色素下降幅度不大,复水后光合速率恢复较快,非光化学淬灭参数和保护酶活性大幅度上升,气孔导度和蒸腾速率显著下降,WUE和qN明显上升,这表明辣椒对干旱有较强的适应力;同时发现不同栽培种间的抗旱能力存在一定的差异,CB的光合色素、光合速率和气孔导度下降幅度最小,非光化学淬灭参数和水分利用率上升幅度最大,这表明CB比其他栽培种的抗旱能力强;研究同时发现,野生种Capsicum baccatum var.baccatum(CBY)的耐旱能力比5个栽培种都强。研究结果表明,辣椒育种应加强栽培种间以及栽培种与野生种之间的基因交流,达到提高产量和品种的抗逆能力的目的。     

高温胁迫对不同热敏型辣椒同工酶及DNA甲基化的影响

分别以耐热型晚熟紫色辣椒‘7036’和热敏型早熟绿色辣椒‘9050’为材料,研究了40℃高温胁迫对其POD同工酶以及DNA甲基化表达的影响。结果显示:(1)在POD同工酶表达方面,未经高温胁迫的辣椒‘7036’比其它处理多出1条带,而同工酶活性在2种辣椒中呈现不同的变化趋势。(2)随着高温胁迫时间延长,辣椒‘7036’DNA无甲基化和全甲基化比率增加,半甲基化和总甲基化比率降低,而辣椒‘9050’只有高温处理7d(T_7)的甲基化水平变化与之类似,但半甲基化和全甲基化比率的绝对值远低于辣椒‘7036’。(3)高温处理7d的DNA甲基化模式中,辣椒‘7036’去甲基化C型条带比率较高,辣椒‘9050’以超甲基化B型条带为主。实验表明,高温胁迫下紫色辣椒‘7036’的POD同工酶活性恢复,半甲基化水平大幅下降和全甲基化水平快速上升以及去甲基化等变化可能与其耐高温胁迫特性相关。     

异常高温干旱对稻纵卷叶螟迁飞的影响

根据本县稻纵卷叶螟多年发生实况和气象资料,认为高温(29℃以上)促使稻纵卷螟迁飞,但天气异常高温(31℃以上)干旱(降水极少)反而迫使其在本地居留。迁飞代这种反常现象的发生,将较大程度影响下一代的发生程度。这一现象的发现将有助于进一步掌握水稻迁飞害虫的迁飞规律和预测预报技术。     

干旱对中国林蛙体长生长的影响

运用椎骨年轮返算体长方法,分析了干旱年,正常年天津蓟县中国林蛙第1至第3年龄体长增长量。结果表明,干旱年体长生长减缓,t-检验差异显著或差异极显著。证实了代偿性生长在两栖类上存在。做不同年份体长分布频率图比较之间差异,干旱年秋季出现大量体长极小的性成熟个体♂♂＜41mm,♀♀≤40mm,干旱年中国林蛙种群优势年龄组比正常年的推迟一年。     

Cd2+胁迫对小麦幼苗生长及呼吸作用的影响

以小麦品种郑州9023为材料,研究了不同浓度Cd2 胁迫对小麦幼苗生长及呼吸作用的影响.结果显示:(1)随Cd2 胁迫浓度的升高,小麦幼苗根和芽的呼吸速率及琥珀酸脱氢酶(SDH)活性均呈先上升后下降的趋势.(2)Cd2 胁迫对小麦幼苗根中细胞色素氧化酶(COD)、苹果酸脱氢酶(MDH)、异柠檬酸脱氢酶(IDH)同工酶表达的影响较小,都呈低浓度诱导、高浓度抑制的效应,且Cd2 处理诱导了根中新的MDH、IDH同工酶带的表达;而不同浓度Cd2 对小麦幼苗芽中COD、MDH、IDH同工酶的表达影响较小.(3)随Cd2 胁迫浓度的增加,芽长、根长、芽干重、根干重均呈持续下降的趋势,且对根的抑制作用明显大于对芽.研究表明,Cd2 胁迫可以改变小麦幼苗根和芽中SDH、COD、MDHI、DH等呼吸作用关键酶的活性或同工酶表达,从而影响其呼吸作用,最终抑制了幼苗的生长.     

干旱胁迫对不同基质网袋桢楠幼苗生长及生物量的影响

探讨不同育苗基质下桢楠（Phoebe zhennan）苗木对周期性干旱胁迫的适应能力及生存对策,为筛选抗旱育苗基质提供参考。以耕作土、森林腐殖土、泥炭土、蛭石为原料,按体积比配制成5种育苗基质,T1：耕作土=10（传统桢楠育苗）、T2：森林腐殖土=10、T3：耕作土：森林腐殖土：泥炭土：蛭石=4：3：2：1、T4：耕作土：森林腐殖土：泥炭土：蛭石=3：2：4：1、T5：耕作土：森林腐殖土：泥炭土：蛭石=2：1：6：1,采用随机区组设置干旱胁迫梯度,分析不同胁迫水平对桢楠幼苗生长的影响。结果表明：（1）配比基质的理化性质与苗木生长密切相关,正常浇水时,基质处理苗生长质量均优于传统育苗,但重度胁迫下,仅T3、T4处理苗木生长较好;（2）随着干旱胁迫程度的增加,各基质配比桢楠苗木株高、基径、叶面积、叶面积指数、地上生物量、地下生物量等生长指标均受到抑制,但受影响程度存在差异;（3）各基质处理苗木质量隶属函数值T3 > T4=T1 > T2 > T5,T3基质配比最优,所育苗木生长优良,耐旱抗旱性强,显著提高造林成效。表明适宜的基质配比能够协调植物生长所需的水、肥、气、热,有利于植物在逆境中生存。     

干旱和高温对植物光合作用的影响机制研究进展

干旱(水分亏缺)和高温是我国北方沙漠化地区植物生长季的两个主要环境胁迫因子。本文主要就干旱和高温在生理水平对植物光合作用影响机制的最新研究进展进行了综述,并对以后的相关研究进行了一些分析。     

不同节水灌溉方式对干旱山地板栗生长结实的影响

在山东省泰安市半干旱、半湿润气候区的山地果园,以板栗为试材,研究了陶罐贮水、蓄水穴和畦灌覆盖3种节水灌溉方式下栗园土壤水分特征及对板栗根系、树体生长和结实的影响.结果表明：与畦灌(对照)相比,3种节水灌溉方式均能延长果园土壤保湿时间,其中陶罐贮水处理效果最明显,保湿时间长达32 d,较对照延长13 d.节水处理下,板栗结果枝长度和数量、叶片面积和质量、果前梢混合芽数量等均较对照明显增加.陶罐贮水和蓄水穴处理能对深层土壤根系进行灌溉并诱导深层根系生长,降低了浅层干旱对根系的胁迫.3种节水灌溉均能大幅度提高板栗果实产量,陶罐贮水、蓄水穴和畦灌覆盖处理的产量分别较对照提高18.8%、16.5%和14.2%.     

聚乙二醇、赤霉素、磷酸氢二钾和低温处理种子后的甜椒幼苗生长

聚乙二醇(PEG)、KH2PO4、赤霉素(GA3)和低温处理可以不同程度上提高甜椒二叶一心、四叶一心和六叶一心期的壮苗指数、根系活力、根系吸收面积和叶绿素含量,改善甜椒幼苗的生长;甜椒壮苗指数、根系活力和根系活跃吸收面积与种子活力指数相关性显著,种子活力指数与甜椒苗龄的相关性大小依次为:二叶一心＞六叶一心＞四叶一心期.     

EMS-induced lincomycin resistance in red pepper (Capsicum annuum L.)

Summary Ethyl methane sulphonate (EMS) is a potential mutagen to induce lincomycin resistance in Capsicum annuum. Mutagenized cotyledons were cultured on shoot regenerating medium containing lincomycin (100 mgl⁻¹). Approximately 14% of regenerated shoots were chlorophyll deficient and about 4% of regenerated shoots were green from mutaganized cotyledons. The regenerated green plants were resistant to lincomycin but sensitive to chloramphenicol, kanamycin, spectinomycin, and streptomycin. Reciprocal crosses were made between resistant and sensitive plants. Inheritance of lincomycin resistance was transmitted as a non-Mendelian trait. Lincomycin resistance is a first selectable and maternally inherited organelle encoded genetic marker described in chili pepper. Such mutants should be useful in designing biochemical selection schemes to recover somatic hybrids and cybrids.     

辣椒优良自交系间遗传差异的分子分析

作物自交系间遗传差异的分析与评价是杂种优势育种和杂交育种成功的基础。鲜食尖椒类(Capsicum an-nuumvar.longum)品种是我国辣椒生产的主要品种类型之一。针对我国鲜食尖椒的育种目标,以国内外10份尖椒优良自交系为材料,利用相关序列扩增多态性(SRAP)和简单序列重复(SSR)标记技术对其进行了遗传差异分析。结果显示:SRAP技术具有较高的位点和多态性检测能力,平均每次检测的位点数和多态性位点数分别为34个和10个,是SSR的10倍和5倍;辣椒自交系间基于SRAP标记的遗传距离和基于SSR标记的遗传距离之间的相关程度较低(r=0.144);基于SRAP标记和SSR标记联合数据计算的遗传距离,10个尖椒自交系被分为3大类,这种分类结果与辣椒杂种优势育种实践相一致。本研究结果表明,SRAP具有较高的遗传分析效力;基于不同分子标记遗传分析结果的差异与标记间共享位点的多少有关;10个尖椒自交系的分类结果可用于指导育种实践。     

Tapetum Dimorphism and Its Histochemical Study in Sweet Pepper (Capsicum annuum L. Var. grossum)

In sweet pepper, the portion of tapetum toward the interior of the anther comprising large cells is derived from cells of connective of anther whereas the remaining tapetum on the outside of the anther comprising comparatively small cells is derived from the parietal layer. Those ceils of the former prosessing large vacuoles and large nuclei are stained weaker than the cells of the latter by methyl green-pyronin and mercuric-bromophenol blue staining. Large spherical grains which contain acid phosphatase appear in the vacuoles in both kinds of tapetum at sporogenesis stage. During meiosis of pollen mother cells, DNA, RNA and protein sysntheses increase in tapetum. The tapetum derived from connective accumulates more DNA than that derived from parietal layer. The activity of acid phosphatase becomes higher in tapetum when it degenerates. The degeneration of two kinds of tapetum is similar. There are no starch grains in tapetum through its whole course of development.     

辣椒胞质雄性不育系和保持系内源激素含量的比较

以2个辣椒品系(199807、199803)的胞质雄性不育系和相应保持系为实验材料,采用酶联免疫吸附法(ELISA)测定IAA、(Z ZR)、GA3和ABA等内源激素含量,用气相色谱分析仪测定乙烯(ETH)释放量,对辣椒胞质雄性不育系和相应保持系内源激素含量变化规律进行研究.实验结果表明:在四分小孢子之前,花药中的IAA含量不育系显著高于保持系,在四分小孢子时期花药和花蕾中的IAA含量出现转折,到花粉粒成熟期的花蕾和花药以及开花期叶片中的IAA含量均是不育系显著低于保持系;小孢子各发育时期花药以及花期叶片中GA3含量均是不育系高于保持系,但花粉粒成熟期化蕾中GA3含量为不育系低于保持系;小孢子不同发育时期的花药以及花期叶片中ABA含量始终足不育系显著高于保持系,而花粉粒成熟期花蕾中ABA含量不育系与保持系没有显著差异;花粉粒成熟期的花蕾和花期叶片中ETH释放量表现为不育系显著高于保持系.同时,花粉粒成熟期的花蕾、花药和叶片中IAA/ABA、(Z ZR)/ABA、GA3/ABA、IAA/GA3、(Z ZR)/GA3等5个激素的比值均有不育系低于保持系的趋势.本实验结果说明辣椒的育性表现与花器和叶片等组织中内源激素的含量变化有关,花药和花期叶片中IAA亏缺、GA3和ABA增加以及化蕾和叶片中ETH过度产生,都有可能导致辣椒雄性不育.     

甜椒胞质雄性不育雄配子发育的解剖学和超微结构研究

运用石蜡切片和电子显微镜超薄切片方法观察了甜椒(Capsicum annuum L．)细胞质雄性不育系8A和保持系8B雄配子发育过程。结果表明：不育系和保持系都能正常进行减数分裂,绒毡层细胞无明显差异,形成了正常的四分孢子。在四分体单核居中期后,不育系的绒毡层细胞异常膨大并伸进药室,挤压花粉粒,同时绒毡层细胞提前降解,不育系单核晚期花粉粒开始崩出内含物。致使不育系的雄配子在双核花粉粒形成之前就完全裂解,不能发育成正常的花粉粒。此外,超薄切片还观察到不育系花粉粒在单核早期绒毡层细胞线粒体空泡化,这种变化表明雄性不育的遗传缺陷包括在花药发育早期发生的线粒体结构变化。     

Evolution of Capsaicinoids in Peter Pepper (Capsicum annuum var. annuum) During Fruit Ripening

The evolution of individual and total contents of capsaicinoids present in Peter peppers (Capsicum annuum var. annuum) at different ripening stages has been studied. Plants were grown in a glasshouse and the new peppers were marked in a temporal space of ten days. The extraction of capsaicinoids was performed by ultrasound‐assisted extraction with MeOH. The capsaicinoids nordihydrocapsaicin (n‐DHC), capsaicin, dihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin were analyzed by ultraperformance liquid chromatography (UHPLC)‐fluorescence and identified by UHPLC‐Q‐ToF‐MS. The results indicate that the total capsaicinoids increase in a linear manner from the first point of harvest at ten days (0.283 mg/g FW) up to 90 days, at which point they reach a concentration of 1.301 mg/g FW. The evolution as a percentage of the individual capsaicinoids showed the initial predominance of capsaicin, dihydrocapsaicin, and n‐DHC. Dihydrocapsaicin was the major capsaicinoid up to day 50 of maturation. After 50 days, capsaicin became the major capsaicinoid as the concentration of dihydrocapsaicin fell slightly. The time of harvest of Peter pepper based on the total capsaicinoids content should be performed as late as possible. In any case, harvesting should be performed before overripening of the fruit is observed.     

辣椒净光合速率Hayman双列杂交分析

用辣椒(Capsicum annuum L.)6个亲本,按(1/2)n(n-1)双列杂交法配制15个杂交组合,用Hayman双列杂交分析法估算不同开花结果时期净光合速率的遗传参数。阵列协方差(Wr)对阵列方差(Vr)的回归分析结果表明,辣椒开花结果前期、中期、后期净光合速率的遗传都不符合“加性-显性”模型。Wr Vr与亲本Yr间的相关分析表明含有更多高净光合速率,显性基因的亲本具有较大的Wr Vr值。遗传参数估算表明开花结果时期的净光合速率遗传是显性效应比加性效应更加重要,同时还存在显著上位性效应。狭义遗传力较小,开花结果中、后期杂种优势比前期明显。     

Microspore-derived embryogenesis in pepper (Capsicum annuum L.): subcellular rearrangements through development

Background information. In vitro-cultured microspores, after an appropriate stress treatment, can switch towards an embryogenic pathway. This process, known as microspore embryogenesis, is an important tool in plant breeding. Basic studies on this process in economically interesting crops, especially in recalcitrant plants, are very limited and the sequence of events is poorly understood. In situ studies are very convenient for an appropriate dissection of microspore embryogenesis, a process in which a mixture of different cell populations (induced and non-induced) develop asynchronically.Results. In the present study, the occurrence of defined subcellular rearrangements has been investigated during early microspore embryogenesis in pepper, an horticultural crop of agronomic interest, in relation to proliferation and differentiation events. Haploid plants of Capsicum annuum L. (var. Yolo Wonder B) have been regenerated from in vitro anther cultures by a heat treatment at 35 degrees C for 8 days. Morphogenesis of microspore-derived embryos has been analysed, at both light and electron microscopy levels, using low-temperature-processed, well-preserved specimens. The comparison with the normal gametophytic development revealed changes in cell organization after embryogenesis induction, and permitted the characterization of the time sequence of a set of structural events, not previously defined in pepper, related to the activation of proliferative activity and differentiation. These changes mainly affected the plastids, the vacuolar compartment, the cell wall and the nucleus. Further differentiation processes mimicked that of the zygotic development.Conclusions. The reported changes can be considered as markers of the microspore embryogenesis. They have increased the understanding of the mechanisms controlling the switch and progression of the microspore embryogenesis, which could help to improve its efficiency and to direct strategies, especially in agronomically interesting crops.     

观赏辣椒一步成苗诱导条件的筛选

采用正交试验设计方法探讨6-BA、NAA和2,4-D对观赏辣椒一步成苗影响的结果表明:6-BA与NAA的浓度比对丛生芽诱导的影响最大。筛选出的观赏辣椒一步成苗的最适培养基为1/2MS 1.0mg·L-16-BA 0.5mg·L-1NAA 0.2mg·L-12,4-D,并获得移栽后的成活植株。