谷氨酰胺、脯氨酸和激素对苜蓿花药培养的影响

为提高苜蓿(Medicago sativa L.)花药培养效率,以小孢子发育处于单核中期到单核靠边期的花药为材料,对谷氨酰胺、脯氨酸和激素配比对花药培养的影响进行研究。结果表明:培养基中附加谷氨酰胺或脯氨酸对苜蓿花药愈伤组织诱导、增殖和分化都是有益的,其中谷氨酰胺700 mg/L或脯氨酸600 mg/L的效果较佳;增殖培养基中附加2 mg/L 2,4-D和0.5mg/L 6-BA配合使用较单独使用更有利于愈伤组织增殖和后期绿苗分化;分化培养基中附加0.5 mg/L NAA和2 mg/L KT的绿苗分化率较高。     

小麦品种抗旱性鉴定指标遗传规律研究

依据Griffing方法I配制种植不同类型的复合双列杂交组合,在人工模拟干旱棚和田间自然干旱条件下,分别设水、旱2种水分条件。在不同生育时期测定株高、株穗数、株粒重、穗粒数、黄叶片数、SOD、POD、MDA等农艺、生理生化性状,研究不同组合类型对杂交后代的遗传力影响及其与抗旱性的关系及遗传规律。结果表明,可采用抗旱指数(DRI)作为评价小麦品种抗旱性强弱的指标。旱地株粒重、旱地穗下节长、旱地黄叶片、籽粒饱满度、落黄、旱地成穗数、旱地株高等7个质量性状和数量性状与抗旱性关系密切且遗传力较强,可作为高产种质杂种后代的早期抗旱性鉴定指标。SOD活性和MDA含量由于广义遗传力和狭义遗传力均较高,可以在杂种后代早期世代进行选择,OA能力和POD活性广义遗传力较高但狭义遗传力低,适宜在杂种后代的晚期世代进行选择。     

Production of mutants with high cold tolerance in spring canola (<Emphasis Type="Italic">Brassica napus</Emphasis>)

A major factor affecting spring canola (Brassica napus) production in Canada is killing frosts during seedling development in the spring and seed maturation in the fall. The objective of this study was to explore the possibility of producing spring canola lines with mutations that have altered biochemical pathways that increase cold tolerance. The approach was to generate UV point mutations in cultured microspores followed by chemical in vitro selection of individual mutant microspores or embryos resulting in measurable alterations to various biochemical pathways with elevated levels of key defense signaling molecules such as, salicylic acid (SA), p-Fluoro-d,l-Phenyl Alanine (FPA), and jasmonic acid (JA). In addition, since proline (Pro) is known to protect plant tissues in the cold-induced osmotic stress pathway, mutants that overproduce Pro were selected in vitro by using three Pro analogues: hydroxyproline (HP), azetidine-2-carboxylate (A2C); and, 3,4-dehydro-d,l-proline (DP). Of the 329 in vitro selected mutant embryos produced, 74 were identified with significant cold tolerance compared to their donor parents through indoor freezer tests at −6°C, and 19 had better winter field survival than winter canola checks. All chemically selected mutant doubled haploids with increased cold tolerance compared well with parent lines for all seed quality and agronomic parameters. Development of increased frost tolerant cultivars should allow for spring canola to be produced in western Canada without compromising seed quality.     

5个一串红品种耐热性鉴定

一串红是夏季园林常见花卉,2008年北京奥运会召开期间正值北京地区夏季高温天气,为使一串红发挥出很好的景观效应,选用耐热性好的品种是关键措施之一。通过对自育的1120#、12#、73#品种和国外引进的展望、王后共5个一串红品种在热胁迫处理下叶绿素含量、电导率、MDA和脯胺酸含量测定,结果表明,随着热处理时间延长,展望和王后叶片叶绿素下降速度最大、细胞膜伤害率上升最快、MDA含量达最大、脯氨酸含量增幅较小,是最不耐热的2个品种,1120#、12#和73#品种耐热性较好。这种耐热性差异在北京地区夏季盆花生产中也得到证实。因此,在夏季高温季节种植一串红,建议选用耐热性较好的1120#、12#和73#品种。     

玉米对低温胁迫的生理响应及不同品种间耐低温能力比较

以中国北方普遍种植的5个玉米品种为供试材料,探索玉米在低温胁迫下的生理响应规律,测试并分析了玉米苗期的光合速率、电导率、脯氨酸浓度的变化,并以此特性参数为依据对作物的抗低温特性进行综合评价。所得到的基本结论如下：光合速率降低幅度较小、电导率增加幅度较低、脯氨酸浓度提高显著的品种,具有较强的抗低温特性;试验中所采用的5个玉米品种,其抗低温冻害能力由强到弱依次为：沈单10号,中单306,农大108,晋单32,陕单902。     

盐胁迫下不同耐盐性葡萄砧木丙二醛和脯氨酸含量的变化

采用水培法,对5种不同耐盐性葡萄砧木品种的一年生苗进行不同浓度的氯化钠胁迫处理,测定叶片中MDA和Pro含量的变化。结果表明,在NaCl胁迫下,不同耐盐性葡萄砧木品种的MDA和Pro含量变化不同。NaCl胁迫对高抗品种ZM01-1的MDA含量影响较小,MDA含量处于一个比较稳定的水平,而其他品种的MDA变化幅度大。因此,可以把MDA含量的相对稳定作为葡萄耐盐性鉴定的辅助指标。NaCl胁迫下Pro含量呈波动式变化,在0.1%NaCl条件下,高抗品种ZM01-1的Pro积累少,在0.3%NaCl条件下ZM01-1的Pro积累多,所以Pro不宜作为葡萄耐盐性鉴定指标。     

重金属对蒲公英种子萌发及叶片渗透调节物质含量的影响

采用水培法利用发芽和出苗试验,研究不同浓度的重金属Hg2+、Pb2+、Cr3+、Cd2+、Cu2+、Zn2+对蒲公英种子萌发及幼苗生长的影响.结果表明:重金属对蒲公英种子萌发有低浓度的促进效应和高浓度的抑制效应.当重金属浓度很低时不影响种子的发芽指数,随着重金属浓度的提高,发芽指数、发芽势、发芽率均会降低, 叶片内的脯氨酸含量均显著增加.可溶性糖含量呈现先上升后下降的趋势.总体上来看,Hg2+的毒性最强,对蒲公英种子萌发的影响程度依次为Hg2+>Cd2+>Pb2+>Cr3+>Cu2+>Zn2+.     

Silicon fertilization modulates 2-acetyl-1-pyrroline content,yield formation and grain quality of aromatic rice

Present study aimed to assess silicon (Si) mediated yield, grain quality and regulations in 2-acetyl-1-pyrroline accumulation (2-AP) in aromatic rice. Four different levels of Si at 15, 30, 45 and 60 mg kg⁻¹ were applied to two aromatic rice cultivars i.e., Nongxiang 18 and Meixiangzhan 2, while pots without Si were served as control (CK). Results revealed that Si fertilization improved 2-AP, Si and proline contents in leaves and grains as well as activities of proline dehydrogenase (PRODH) and net photosynthetic rates (Pn) (in leaves) while interfered with total N contents in leaves and grains. Moreover, leaves N and proline contents, and net photosynthetic rates (Pn) were decreased with plant age i.e., tillering > flowering > maturity while PRODH activities and Si contents were highest at flowering and maturity stages, respectively and minimum at tillering stage. Furthermore, growth, yield and quality components were also improved by Si application but results were not consistent regarding grain quality for both rice cultivars. Further, Si contents in leaves have significant positive relations (r = 0.3974, P < 0.05) with grain 2-AP contents at flowering stage. Hence, Si proved better for both rice cultivars whereas 2-AP contents were higher for Meixiangzhan 2 than Nongxiang 18.     

NaCl胁迫对棉花幼苗生理特性的影响

利用不同浓度NaCl处理中熟棉N181,分析被处理棉花幼苗保护酶活性及MDA、脯氨酸含量的变化,为抗盐新品种的选育提供理论基础.结果表明,经不同浓度NaCl处理后,棉花幼苗叶片中POD、SOD活性和MDA、脯氨酸含量均有明显变化,当0.3％ NaCl胁迫处理3天时,各处理之间差异显著,保护酶活性及脯氨酸含量明显增加,MDA含量降低,说明中熟棉N181在0.3％的NaCl胁迫处理下具有一定耐性.     

越冬期抗寒性不同冬小麦品种间生理指标的比较

以抗寒性不同的4个冬小麦品种为材料,对其在越冬期间叶鞘内丙二醛、可溶性蛋白和脯氨酸生理指标的含量进行测定,以分析高寒地区冬小麦抗寒性的遗传改良潜力.越冬期间,抗寒性强的品种(系)的丙二醛含量较低,可溶性蛋白含量较高；在低温驯化期抗寒性强的品种脯氨酸含量迅速增加,在越冬期各品种脯氨酸含量均保持较高水平.