大白菜耐热性的生理研究＊Ⅱ．叶片水分和蛋白质代谢与耐热性

通过测定耐热性不同的３个大白菜品种在高温胁迫下发生的水分和蛋白质代谢的变化，表明耐热的亚蔬１号比不耐热的“１０６”品种叶细胞具有更高的含水量和束缚水、较大的气孔密度和蒸腾速率、较低的蛋白质降解速率，较耐热的华湘１号的各项生理指标均居于中间水平．高温使细胞膜透性稍有增大，耐热与不耐热品种膜透性增大可能有不同机理．高温胁迫使耐热品种脯氨酸含量迅速增多，脯氨酸可作为大白菜耐热性鉴定的生化指标     

吡虫啉和多菌灵单施及同时施用对番茄生长的影响

在实地调研的基础上,以山东寿光当前普遍栽种的两个番茄品种中杂9号和中杂106号为指示植物,研究了当地施用较典型的杀虫剂吡虫啉和杀菌剂多菌灵单施及同时施用对番茄生长及生理生化指标的影响.结果表明:吡虫啉在0～0.07 mg· L-1范围内、多菌灵在0～0.4 mg· L-1范围内,无论单施或同时施用对两个番茄品种的植株鲜重和叶绿素含量都有一定的促进作用;吡虫啉超过0.14 mg·L-1、多菌灵超过0.8 mg·L-1,随着单施或同时施用浓度的提高,对两个番茄品种的植株鲜重和叶绿素含量的抑制作用越来越明显,且中杂9号番茄对吡虫啉和多菌灵的耐受性高于中杂106号番茄.如中杂106号番茄B2.8D1.6处理的植株鲜重仅为B0.035D0.2处理的20％,B2.8D1.6处理的叶绿素含量仅为对照处理的8％.两种番茄的过氧化物酶活性均随吡虫啉浓度的增加而显著增加(P＜0.05),多菌灵在试验处理浓度范围对其影响不显著.吡虫啉和多菌灵单施或同时施用均显著提高了中杂9号番茄过氧化氢酶活性(P＜0.05),而中杂106号番茄由于本身过氧化氢酶活性较高,农药的施用对其酶活性影响并不显著.两种番茄的丙二醛含量和细胞膜透性比较高,施用农药对二者影响相对较小.单施B2.8、单施D1.6以及同时施用B2.8D1.6后中杂106号番茄的游离脯氨酸含量显著提高(P＜0.05),分别是对照处理的2.4、2.4倍和2.6倍.     

外源脯氨酸对大叶樟幼苗碱胁迫的缓解效应研究

以1年生大叶樟幼苗为材料,在150 mmol/L Na₂CO₃处理条件下,外源喷施不同浓度的脯氨酸溶液,14 d后测定植物叶片叶绿素含量、叶绿素荧光参数、渗透调节能力及抗氧化能力,分析脯氨酸对大叶樟碱胁迫的缓解效应及其机理。结果表明：适宜浓度外源脯氨酸明显降低碱胁迫下大叶樟幼苗的相对电导率和MDA含量,提高叶绿素含量、F_o、F_m、F_v/F_m、q_N、q_P,提高可溶性糖含量、可溶性蛋白含量、苹果酸含量和脯氨酸含量,提高SOD、POD、CAT活性和总抗氧化能力,降低PAL活性;高浓度脯氨酸明显降低碱胁迫下大叶樟幼苗相对电导率、MDA含量和F_v/F_m,提高F_o、F_m、q_N、SOD活性、POD活性和可溶性糖含量,而叶绿素含量、q_P、可溶性蛋白含量、脯氨酸含量、苹果酸含量、CAT活性、总抗氧化能力、PAL活性与对照差异不显著;隶属函数法综合评价结果表明,抗碱综合评价值D在150 mmol/L脯氨酸处理时达最高值0.917。因此,外源喷施150 mmol/L的脯氨酸能缓解大叶樟幼苗碱胁迫,苹果酸参与脯氨酸缓解大叶樟幼苗碱胁迫过程。     

我国几个不同地域长梗扁桃苗木的抗寒性研究

分别取自河北、固阳、神木、榆林、乌审旗5地生长状况基本相同的长梗扁桃1年生休眠枝条为材料,通过人工冷冻模拟外界环境,对长梗扁桃枝条进行-15℃、-19℃、-23℃、-27℃、-31℃、-35℃、-39℃等7个温度梯度处理.测得这些休眠枝条的相对电导率、SOD、POD活性、游离脯氨酸含量及MDA含量,并对低温处理过的部分枝条进行恢复生长来测定其萌芽率,最后对测定结果进行分析和比较.结果表明:5个地区的长梗扁桃的相对电导率、SOD、POD活性、游离脯氨酸含量及MDA含量均随着处理温度的降低而呈现上升趋势,并且抗寒性强的地区的长梗扁桃SOD、POD活性和游离脯氨酸含量相对较高,MDA含量和电导率较低,恢复生长枝条的萌芽率均比同温度处理下的抗寒性弱的高.抗寒性强弱顺序为:河北(H)＞乌审旗(W)＞固阳(G)＞神木(S)＞榆林(Y),河北和乌审旗的长梗扁桃抗寒性较强,可以对其进行广泛的品种选育和推广.     

镉胁迫对蒙山茶树生长及叶片生理指标的影响

通过盆栽试验,研究不同镉浓度对蒙山茶树生长及叶片生理特性的影响。结果表明:低浓度镉对茶树无明显毒害作用,当镉浓度达到60 mg/kg时,茶树植株受毒害基本死亡;春茶叶绿素含量加镉处理大多高于对照,其增加量先高后低;夏茶叶绿素总量随镉浓度的增加极显著降低,叶绿素含量与添加镉的量呈显著负相关,其相关系数r=-0.997;春茶、夏茶的丙二醛(Malondialdehyde,MDA)含量随镉处理浓度增加显著增加,其正相关系数分别为r=0.970,r=0.994(P<0.01);春茶游离脯氨酸含量随添加镉浓度的增加显著增加,相关系数r=0.829(P<0.05),夏茶游离脯氨酸在镉试验浓度下极显著增加,其相关系数r=0.980(P<0.01),且夏茶游离脯氨酸含量明显高于春茶;春茶可溶性糖都高于对照,其增加量先高后低.,相关系数为r=-0.342;夏茶可溶性糖呈下降趋势,其相关系数r=-0.909(P<0.05)。     

Some Morpho-Physiological Characteristics of Mung Bean Mycorrhizal Plants under Different Irrigation Regimes in Field Condition

In this study we determined some morpho-physiological characteristics of mung bean plants under various irrigation regimes (irrigation after 50, 100, 150 and 200 mm evaporation from pan class A) and mycorrhizal fungi inoculation (Glomus mosseae, Glomus intraradices). The highest and lowest seed yield was obtained from plants irrigated after 50 and 200 mm evaporation from pan, respectively. Root dry weight, root volume, leaf phosphorus and relative water content were decreased in plants under water deficit stress. Whereas, under various level of severe water deficit the proline content, total soluble carbohydrates and leaf nitrogen were increased. Mycorrhizal colonization was observed to be higher in well-watered plants rather than in stressed plants. Furthermore, the mycorrhizal plants produced a higher seed yield (161 g/m²), leaf phosphorus, leaf nitrogen, chlorophyll index, proline, total soluble carbohydrates content, relative water content, root length, root volume, root dry weight and root/shoot weight ratio as compared with non-mycorrhizal plants.     

Boron-induced improvement in physiological,biochemical and growth attributes in sunflower (Helianthus annuus L.) exposed to terminal drought stress

Terminal drought stress (drought at reproductive growth stage) has been considered a severe environmental threat under changing climatic scenarios and undoubtedly inhibits sunflower production. A field study was conducted to explore the potential role of foliar applied boron (B) (0, 15, 30, 45 mg L^?1) at late growth periods of sunflower in alleviating the adversities of terminal drought stress (75, 64, 53 mm DI) grown from inflorescence emergence to maturity stages. The plant water relations such as leaf relative water content (RWC), water potential (Ψ_w), osmotic potential (Ψ_s), and turgor pressure (Ψ_p) were increased significantly with B foliar sprays while exposed to terminal drought stress. Foliar B application considerably improved the nitrogen and B concentrations in leaf and seed tissues, and also chlorophyll a and b pigments under terminal drought stress conditions. Drought-induced proline accumulation prevented the damages caused by drought stress, nevertheless, B foliar spray increased its contents. Compared to well-watered conditions, terminal drought stress substantially declined the growth performance in terms of reduced leaf area index (LAI), crop growth rate (CGR), net assimilation rate (NAR), and total dry matter (TDM) production; however, foliar B supply (30 mg L^?1) might be helpful for improving drought tolerance in sunflower with reduced growth losses.     

辣椒细胞质雄性不育系与保持系生化特性研究

为探明辣椒细胞质雄性不育的败育机理，对辣椒细胞质雄性不育系与保持系叶片和不同发育时期的花蕾的可溶性糖、蛋白质和脯氨酸含量的测定以及对过氧化物酶活性的分析，发现随着花蕾的发育，不育系大花蕾期可溶性糖含量明显低于小、中花蕾时期，而保持系可溶性糖含量则保持一直升高的态势；不育系小花蕾蛋白质的含量较中、大花蕾时期高，而保持系花蕾蛋白质的含量一直升高；不育系脯氨酸含量略有下降，而保持系花器中游离脯氨酸迅速积累，含量明显高于不育系；POD活性是不育系明显高于保持系，且呈持续增强趋势，保持系逐渐减弱。     

不同玉米杂交种孕穗、开花和灌浆期抗旱性研究

通过在水分胁迫下不同玉米杂交种在孕穗、开花和灌浆期抗旱性比较试验,结果表明,抗旱性较强的豫玉3号,在3个关键时期水分胁迫下其产量损失较小,而不抗旱杂交种新黄单85—1和丹玉13号减少幅度较大。这种产量变化趋势与其内部的生理生化反应表现一致:水分胁迫时豫玉3号气孔阻力增加幅度大,水势下降幅度小,脯氨酸含量明显升高,从而提高了渗透调节能力:细胞内SOD活性下降幅度较小,丙二醛(MDA)含量增加也较少。