云南不同茶区茶树种质资源的红碎茶香气成分研究

为了探讨云南不同茶区茶树种质资源的红碎茶香气成分特征物质及种质间香气组成的差异,采用GC/MS方法,对保存于国家种质大叶茶树资源圃内云南省11个县共16份茶树种质资源的红碎茶香气成分进行了比较分析。结果表明：构成云南红碎茶香气特征性物质主要是芳樟醇、(E)－2－己烯醛、苯乙醛、香叶醇、反式氧化芳樟醇、雪松醇、水杨酸甲酯、顺式氧化芳樟醇、正己醛、橙花叔醇。香气指数（FI）聚类分析,可把16份种质的红碎茶香型划分为三种类型：（１）高芳樟醇及其氧化物含量类型;（２）高芳樟醇及香叶醇含量类型;（３）高(E)-2-已烯醛含量型。 萜烯指数（TI）分析表明,保山市和临沧市的红碎茶香气特征较为接近,西双版纳州、德宏州、普洱市的红碎茶香气特征较为接近。综上,云南不同茶区茶树种质资源的红碎茶香气存在地方风格,红碎茶香气地方风格的存在与各地栽培的地方品种资源不同有关。     

高能电子辐照对猕猴桃保鲜效果的影响

为探讨高能电子束对猕猴桃贮藏品质及生理生化的影响,以‘红阳’猕猴桃为试材,采用250、500、1000、1500 Gy 等不同剂量高能电子束辐照猕猴桃,置于温度为(1±1)℃、湿度85%~90%冷库中贮藏,研究不同剂量高能电子束辐照对猕猴桃保鲜效果的影响。结果表明,500~1000 Gy电子束辐照剂量为猕猴桃保鲜的适宜使用范围,结合冷藏温度为(1±0.5)℃、相对湿度为80%~90%贮藏技术,可显著降低果实的呼吸强度,显著抑制果实硬度、可溶性固形物、可滴定酸及Vc含量的下降;对果皮及果肉叶绿素的降解有较强的抑制作用,减缓了贮藏期间果肉的褐变,较好地保持了膜完整性,有效地控制了猕猴桃采后的软化衰老进程,减少了其贮藏期间的腐烂变质,保持了果实鲜艳的外观色彩和果肉色泽。其中辐照剂量为500 Gy的电子束辐照处理结合低温贮藏,可使猕猴桃的安全保鲜期由原来的30 天（腐烂率低于10%）延长至80 天（腐烂率为0）,Vc含量可达129.62 mg/100 g。1500 Gy的电子束辐照剂量在一定程度上对果实造成了伤害,为猕猴桃辐照保鲜工艺的临界点。     

银杏种实生长发育过程中内源激素含量的变化

该研究选择银杏核用主栽品种佛指的成年结实树为试验材料,采用ELISA测定种实生长发育过程中内源激素含量变化及其在种实中的分布差异,结果表明:银杏种实的纵、横径和单粒重的累积生长都呈单S型曲线.银杏外种皮中IAA、CA3和ABA含量高于种仁中含量,其差异达到显著或极显著水平;无论是胚珠,还是外种皮和种仁,其IAA和CA3的含量都高于ABA含量;银杏胚珠、外种皮及种仁中IAA、GA3、ABA含量的变化基本与细胞和种实的生长发育变化相一致,IAA和GA3含量明显上升时,种实开始旺盛生长;IAA、CA3和ABA含量出现全年最大值时,种实进入旺盛生长阶段,胚乳组织形成,薄壁细胞中的淀粉体数量增加,种实生长旺盛末期到来.     

不同花生品种(系)荚果和子仁内源激素含量变化与干物质积累特征分析

以3个荚果和子仁生长发育正常的花生栽培品种(系)和种子皱缩变异品系05D677为材料,测定其荚果和子仁生长发育过程中激素含量与干物质积累变化特征,分析其内源激素含量变化与干物质积累关系,探讨变异品系05D677中内源激素含量变化对荚果和子仁生长发育的影响。主要结果如下：(1)果针入土24~60 d是荚果和子仁干物质快速积累期,期间山花15、05D610和白沙1016荚果干物质积累速率(_PK_W)平均值与子仁干物质积累速率(_KK_W)平均值均极显著大于05D677;3个正常品种(系)_PK_W和_KK_W最大值均出现在果针入土30 d,05D677出现在果针入土36 d。(2)4个品种(系)幼果或子仁内细胞分裂素(Z+ZR)、赤霉素(GA)、生长素(IAA)、脱落酸(ABA)含量变化趋势基本相同,其中05D677的GA含量峰值出现时间比3个正常品种(系)晚6 d;05D677的Z+ZR、GA、ABA含量最高值均极显著低于3个正常品种(系),其IAA含量最高值极显著高于3个正常品种(系)。(3)荚果膨大中后期,_PK_W和_KK_W与Z+ZR、GA、ABA含量呈极显著正相关,与IAA呈极显著负相关;荚果充实初期,Z+ZR含量与_PK_W和_KK_W呈极显著正相关;GA含量在荚果充实后期和成熟期与_PK_W呈极显著正相关;ABA含量在荚果充实后期与_PK_W和_KK_W均呈极显著负相关,在成熟期与_PK_W呈极显著正相关。(4)与3个荚果和子仁发育正常的品种(系)相比较,05D677幼果迅速膨大期和子仁充实初期的IAA含量明显升高,且Z+ZR、GA和ABA含量不足可能引起内源激素比例失衡,影响荚果和子仁的生长,致使荚果和子仁发育进程延迟、干物质积累速率的极显著降低,表现为收获时荚果充实度差,种子皱缩。     

脱落酸与赤霉素对瓜尔豆叶片光合作用及内源激素的影响

通过大田随机区组试验设计,在管理、密度、肥水等条件一致的情况下,在瓜尔豆始花期、盛花期、盛荚期和鼓粒期叶面喷施不同浓度的脱落酸与赤霉素,研究其对瓜尔豆叶片光合作用及内源激素的影响,旨在为利用植物生长调节剂对瓜尔豆的高产栽培提供理论依据。试验结果表明,不同浓度的脱落酸处理均能在各个生育时期降低植株叶片的净光合速率和蒸腾速率,关闭气孔,从而抑制其光合作用;而不同浓度的赤霉素处理能明显地增加植株叶片的净光合速率和蒸腾速率,促进其光合作用;脱落酸与赤霉素处理均能降低叶片叶绿体含量,并且赤霉素处理降低更显著。不同浓度的脱落酸处理降低了植株叶片内源吲哚乙酸、赤霉素和激动素的含量,升高了内源脱落酸的含量;而不同浓度的赤霉素处理增加了植株叶片内源吲哚乙酸、赤霉素和激动素的含量,降低了脱落酸的含量,在调节激素动态平衡的基础上对植株进行调控。     

细胞膜透性和两种内源激素对硬肉桃果实成熟前后硬度变化的影响

以硬肉桃新品种‘双久红’和常规品种‘川中岛白桃’（对照）果实为试材,分别对两品种果实成熟前后20d内的果实硬度、MDA、相对电导率及ABA、GA含量进行了测定。结果表明,自成熟前15d开始,‘双久红’果实的MDA、相对电导率、ABA含量均极显著低于‘川中岛白桃’的（P <0.01）;而前者的GA含量则是极显著高于后者（P <0.01）。相关性分析表明,两品种桃果实硬度与MDA、相对电导率、ABA含量呈极显著负相关（P <0.01）; 而GA含量与前者呈极显著正相关,与后者仅达到显著正相关水平（P <0.05）。     

水分胁迫对花生幼苗叶片内源激素含量的影响

研究了水分胁迫对花生幼苗叶片内源激素含量的影响。结果表明,GA3含量先升后降,出现了两个高峰值,ABA含量则逐渐升高,IAA和ZR先降低后升高。随着胁迫时间的延长,叶片中ABA/IAA的值先升后降,ABA/ZR逐渐升高。     

光周期对大豆叶片内源激素含量及其平衡的影响

选用生育期不同的３个品种，采用酶联免疫检测技术（ＥＬＩＳＡ），研究了开花前和开花后光周期处理对大豆叶片内源激素含量及其平衡状况的影响。结果表明，短日照与长日处理相比，脱落酸（ＡＢＡ）含量显著上升，赤霉素（ＧＡ１＋３）含量及ＧＡ／ＡＢＡ比例明显下降，细胞分裂素（ＤＨＺＲ，二氢玉米素核苷）有下降趋势，生长素（ＩＡＡ）的变化不大。短日下ＧＡ和ＩＡＡ含量负相关，ＧＡ与ＡＢＡ正相关，长日下ＩＡＡ与ＤＨＺＲ负     

外源GA3、ABA对种子发芽与亲本穗上发芽内源激素变化影响研究

以外源GA3和ABA处理种子和水稻亲本,研究GA3和ABA对水稻种子萌发及亲本穗上发芽的影响,结果表明,外源GA3处理后引起两者种子内源GA3升高,降低种子内ABA、IAA水平,提高了GA3/ABA比值;外源ABA处理,引起种子内ABA含量升高,降低GA3、IAA水平,GA3/ABA比值减少;种子萌发和穗芽形成过程中GA3含量、GA3/ABA比值对比,发现前者小于后者,而种子萌发率与穗芽率相比,前者远远大于后者,表明穗上穗芽形成是一个更为复杂的生理变化过程.     

红掌叶片离体培养过程中内源激素含量的变化

应用酶联免疫吸附测定法(ELISA)研究了红掌叶片愈伤组织诱导和植株再生过程中内源激素的含量变化。结果表明:内源激素IAA,GA3,ABA,ZR在幼嫩叶片内的含量均较高;而在愈伤组织诱导阶段,4种内源激素均呈下降趋势;在植株再生过程中,内源IAA和GA3含量继续下降,ABA和ZR含量的变化因品种而异,粉冠军内源含量开始回升,亚历桑娜则继续下降至最低水平;在小苗移栽后,粉冠军的4种内源激素含量均急剧回升并保持较高水平,亚历桑娜中内源IAA和GA3含量继续下降至最低水平,而内源ABA和ZR含量回升保持较高水平。     

根结线虫侵染对黄瓜生长和内源激素含量的影响

通过酶联免疫吸附法测定根结线虫侵染后48h内的黄瓜体内的各种内源植物激素含量的变化,探索黄瓜根结线虫病害产生的生理应答机制。通过外部形态结果观察看到根结线虫侵染后,黄瓜生长缓慢,植株矮小,并且提前衰老。同时,黄瓜叶片中的内源植物激素含量在48h内也发生了较大变化:黄瓜叶片中茉莉酸的含量在线虫侵染16h内急剧上升,上升幅度高达对照的8.2倍,而水杨酸、脱落酸和异戊烯基腺苷在侵染后含量有显著上升的趋势,并在24h达到各自的峰值;但是生长素和赤霉素含量仅短暂升高,其余时间显著低于对照。通过测定浸染初期各内源植物激素之间的动态平衡,可以为研究植物诱导抗病性提供理论参考。     

甜瓜果实中乙烯生产量及一些相关性状的遗传分析

为改进甜瓜货架期,利用成熟果实乙烯释放量及变化速率存在显著差异的3个甜瓜变种为亲本,配制了皇后×9-8(非跃变类型材料间)和皇后×Charentais(非跃变类型与跃变类型材料间)两个组合,对各组合F1,F2及回交世代BC果实中乙烯的生成变化及果实脱落性、外果皮迅速黄化等相关性状的遗传变化进行了分析。结果表明,甜瓜果实中乙烯生成量为不完全显性遗传,受两对以上基因控制。在皇后×Charentais组合的F1中,内源乙烯含量在采收1d后表现出急剧升高,同时伴随着外果皮迅速黄化及果柄脱落的发生,根据这些性状在F2及分别与父母本回交世代中的不同分离比率指出,乙烯的跃变类型、外果皮迅速黄化及果柄脱落在甜瓜果实中为显性遗传。     

Phenotypic expression of quantitative and qualitative components of partial resistance to powdery mildew (Sphaerotheca fuliginea race 1) in melon (Cucumis melo) germplasm

A study was conducted to investigate the expression of four components of partial resistance to Sphaerotheca fuliginea race 1 in selected melon (Cucumis melo L.) lines viz. infection frequency, latent period, spore production, and disease-severity score. Those components were evaluated at two developmental stages of the host: the cotyledon stage and the stage of the first two true leaves. Detached plant parts (disks of cotyledons and true leaves) were inoculated using a vacuum-operated settling tower. All four components showed significant variation among genotypes, and correlations between components at both developmental stages were large and significant. The line ‘CNPH 83–095’ (without any major resistance gene to powdery mildew) presented the highest level of partial resistance in both vegetative stages for almost all components evaluated. The lines ‘W-6’ (Pm1Pm1, Pm2Pm2), ‘Cinco’ (Pm1Pm1, Pm2Pm2), and CNPH ‘84–147’ (Pm1Pm1), even though carrying the major gene Pm1 for complete resistance to race 1 of the fungus, showed slight but significant differences for quantitative components of partial resistance at the cotyledonal stage. Different levels of partial resistance may be expressed, even in lines with a major race-specific resistance gene to powdery mildew, in specific developmental stages of the melon plants.     

河套蜜瓜采后生理与保鲜技术研究进展

针对河套蜜瓜成熟和软化机制以及低温贮藏、1-MCP处理、臭氧处理、化学药剂保鲜、转基因技术应用等方面的研究进展分别进行了论述,并对目前存在的若干问题提出了几点建议.     

甜瓜白粉病抗性基因的遗传与分子标记

为了建立甜瓜抗白粉病基因的分子标记辅助选择方法,以杂交组合1A151/恒进红瓤酥的6个世代群体 P1,P2,F1,F2,BCr和BCs为材料,利用风媒接种方法和分群法,研究了抗病基因的遗传和分子标记。结果表明,抗源 1A151对白粉病菌的抗性由1对不完全显性抗病基因控制,并寻找到了1个与抗病基因位点连锁的分子标记RAPD- S329,其距离为6.81±1.67个遗传单位。     

One dominant gene conferring the resistance to the leafminer, Liriomyza trifolii(Burgess) Diptera: Agromyzidae in melon (Cucumis melo L.)

The line Nantais Oblong, a melon of Charentais type, was shown to be a source of resistance by antibiosis to the leafminer, Liriomyza trifolii (Burgess), Diptera, Agromyzidae. We studied the genetic control of this resistance in F2 and back-cross progenies from the cross between Nantais Oblong and Védrantais, a Charentais line susceptible to the leafminer. Tests were carried out on young plants in plastic cages with controlled infestation. Complete mortality of the L. trifolii larvae was used as indicator of plant resistance. Segregation ratios were consistent with monogenic dominant control of the resistance. The symbol Lt for Liriomyza trifolii resistance is proposed.     

Resistance to melon vine decline derived from Cucumis melo ssp. agrestis: genetic analysis of root structure and root response

Melon vine decline is a major soilborne disease that causes severe economic losses around the world. The fungal pathogens Monosporascus cannonballus Pollack et Uecker and Acremonium cucurbitacearum Alfaro‐García, W. Gams et J. García‐Jiménez have been reported as the main causal agents of this disease. A relatively high level of resistance has been reported in Cucumis melo L. ssp. agrestis (Naud.) Pangalo in the Asiatic accession Pat 81. Although specific resistance mechanisms controlling pathogen‐induced root lesions have been characterized in Pat 81, the development of a vigorous and branched root system can also appreciably increase its tolerance to vine collapse. The genetics of root traits related to root vigour and structure were studied in the progeny derived from a cross between Pat 81 and the highly susceptible cultivar ‘Piñonet’ market class ‘Piel de Sapo’(C. melo L. ssp. melo). The inheritance of specific resistance to soilborne fungi was also studied by analysing root response to inoculation employing naturally infested soil. Estimates of the broad‐(H) and narrow‐sense (h²) heritabilities indicated that the majority of the variation for lesion resistance in lateral and fine roots, in the root weight, root length, and the root surface area could be explained by additive effects, whereas dominance is important in plant biomass and resistance to lesions in hypocotyls. Selection for improved root systems conferring resistance and tolerance to vine decline was successfully conducted in BC₁ progeny derived from a Pat 81 בPiñonet’ mating. Moderate values of heritabilities (0.03–0.76) suggest that breeding strategies that combine family and individual selection could enhance genetic progress. As some of the traits analysed exhibited heterosis, breeding methods directed towards recovering hybrid vigour may increase gain from selection.     

Inheritance of resistance to races 1, 2 and 5 of powdery mildew in the melon TGR-1551

The inheritance of resistance to races 1, 2 and 5 of Podosphaera xanthii in the melon TGR-1551 was studied in a cross with the susceptible cultivar 'Bola de oro'. Under artificial inoculation conditions, four phenotypic classes were defined according to the level of fungal sporulation. The segregation ratios for resistance/susceptibility observed in the different populations and the results of the progeny test indicated that resistance to races 1, 2 and 5 of P. xanthii in TGR-1551 was governed by two independent genes, one dominant and one recessive, which means that the genetic control is a dominant–recessive epistasis. This is the first time that a recessive gene that confers resistance to more than one race of powdery mildew has been identified in melon. TGR-1551 could be considered a good genetic source for the development of powdery mildew resistant breeding lines.     

Effect of genotype and light intensity on somatic embryogenesis and plant regeneration in melon (Cucumis melo L.)

The efficiency of 14 commercial cultivars of melon (Cucumis melo L.) for callus induction, plant regeneration and somatic embryogenesis under different photosynthetic photon flux densities (PPFDs) (150 or 50μmol m^?2 s^?1) was investigated. Cotyledonal explants were cultured on a Murashige and Skoog (MS) medium supplemented either with 9.0 μM 2,4-dichlorophenoxyacetic acid and 23.2μM kinetin or with 0.05 μM 2,4-dichlorophenoxyacetic acid and 0.26 μM 6-benzyladenine for the induction of somatic embryogenesis and shoots, respectively. For embryo maturation and root induction, growing callus tissues were transferred on growth regulator-free MS medium. Both genotype and the intensity of light significantly affected the rate of somatic embryo-genesis, embryo maturation and plant regeneration. On average, 12–47 primary globular-stage embryos were produced per mm² of explant surface. Fully developed, cotyledonary-stage somatic embryos were obtained from only three cultivars. Relatively high root induction rates were observed both on the shoot induction medium (11 cultivars) and on growth regulator-free medium (seven cultivars). In contrast, only six cultivars responded positively to the shoot induction treatment. Callus growth and somatic embryogenesis were significantly improved if cultures were incubated under higher PPFD values, although plant regeneration from all cultivars was significantly reduced under the same conditions.     

胞质雄性不育和核雄性不育辣椒内源激素含量的变化

采用酶联免疫吸附法(ELISA)测定和比较分析了CMS和GMS辣椒不育系(株)和相应保持系(可育株)花蕾和叶片中的内源IAA,Z ZR,GA3,ABA含量及比值的变化。结果表明,CMS雄性不育系和保持系花蕾中IAA,Z ZR,GA3和ABA含量的变化趋势与GMS不育株和可育株间变化趋势基本相同,即不育系(株)IAA,Z ZR,GA3和ABA含量低于保持系(可育株);叶片中Z ZR,GA3和ABA含量变化趋势GMS和CMS也基本一致,即不育系(株)中的含量高于保持系(可育株);花蕾中IAA/ABA,(Z ZR)/ABA,GA3/ABA激素比例的变化GMS与CMS也相同,即不育系(株)比值小于保持系(可育株)。说明虽然GMS和CMS辣椒控制雄性不育的基因不同,但在调节雄性不育时激素的变化规律大多相同,辣椒雄性不育在生理生化机理上可能存在一些相同的特点。