几种化学物质诱导马铃薯对早疫病的抗性及其机理研究

以草酸,KCl,FeSO4,K2HPO4作为激发子,就诱导马铃薯块茎对早疫病的抗性及其机理进行了初步研究。结果表明,草酸,KCl,FeSO4均可诱导马铃薯块茎产生对早疫病的抗性,其中20 mmol／L草酸的保护率达到49．38％,80 mmol／L KCl的保护率达到52．94％,40 mmol／L FeSO4的保护率达到51．51％,K2HPO4不能诱导马铃薯块茎抗早疫病。经草酸、 KCl、FeSO4诱导处理后的马铃薯块茎中,POD,PAL,PPO的活性明显高于对照,表明化学物质可能通过提高这3种酶的活性来发挥其诱导抗病作用。     

3种化学物质诱导马铃薯块茎抗早疫病的初步研究

利用苯酚、对氨基苯甲酸和苯甲酸等3种芳香族类化合物作为激发子,对马铃薯块茎抗早疫病的效果进行了探讨,同时分析了诱导处理后马铃薯块茎中与抗病性相关的酶活性的变化。结果表明,供试的3种化合物均在较低浓度下具有较强的诱导抗病作用,苯酚、苯甲酸和对氨基苯甲酸分别在1,0.01和5 mmol/L时诱导的保护率最高,分别达到43.21%,40.72%和28.75%,均与对照差异极显著。经上述浓度的3种化合物诱导处理后的马铃薯块茎中,过氧化物酶(POD)和苯丙氨酸解氨酶(PAL)的活性均有大幅度上升,明显高于对照,表明这些芳香族类化合物可能通过增加马铃薯体内POD和PAL的活性来发挥其诱导抗病作用。     

遮光对辣椒果实中辣椒素及其相关酶的影响

分别在辣椒的定植期、花期、绿熟期、红熟期进行遮光处理,对辣椒素含量及其代谢中相关酶的关系进行研究。结果表明:绿熟期遮光处理辣椒素含量最高,其次是花期遮光、定植期遮光、红熟期遮光,对照的含量最低。绿熟期遮光处理苯丙氨酸解氨酶(PAL)活性最高,花期和定植期遮光次之,再次是对照和红熟期遮光。过氧化物氧化酶(POD)活性,红熟期和定植期遮光最高,其次是对照和花期遮光,绿熟期遮光最低。多酚氧化酶(PPO)活性,对照和红熟期遮光较高,定植期和花期遮光次之,绿熟期遮光最低。由此表明,遮光增加了辣椒素含量,绿熟期遮光效果较好。辣椒素含量高时,PAL活性高,但POD和PPO活性低,表明辣椒素含量与三种酶的活性有相关性。     

水杨酸对黄瓜几种酶活性及抗病性的诱导作用

黄瓜幼苗经水杨酸处理后,ＰＯＤ、ＰＰＯ、ＰＡＬ３种酶活性均有不同程度的变化,与对照相比ＰＯＤ活性在处理后２４ｈ有明显提高,以后一直呈上升趋势,至１４４ｈ后较对照提高１９３．０％。ＰＰＯ活性变化相对较小,酶活性的明显提高在处理４８ｈ以后,处理后１４４ｈ时较对照提高６１．７％。ＰＡＬ在处理后７２ｈ时出现一个小的酶活性峰,较对照提高１７．６％,而后下降,１２０ｈ出现第２个活性峰,较对照提高３０．８％。处理后４ｄ接种霜霉病菌,调查结果表明：第１真叶处理较对照病情指数降低８．９％,第２真叶处理较对照降低２２．１％。     

不同高粱基因型感蚜虫前后POD、PPO、PAL酶活性变化分析

对几个不同高粱基因型田间感蚜虫前后的三种酶POD、PPO、PAL活性进行了测定,结果表明,感蚜前后各材料POD活性都有明显的增加,抗蚜虫材料河农16前后均比其它几个材料的活性低;PPO活性感虫后有明显的增加,变化情况与POD类似;PAL活性感后有明显的增加,河农16与其它几个感蚜型相比,稳定性显著。表明POD、PPO与诱导抗性有关,而PAL在抗蚜材料河农16中为组成型表达的,可能受抗蚜虫基因的控制。     

酵母胞壁多糖对黄瓜植株防御酶系活性的影响

采用浸种和喷雾两种处理方法研究了酵母胞壁多糖对黄瓜植株体内防御酶系的影响,结果表明,浸种和喷雾处理均能提高黄瓜植株体内PAL和PPO活性,有效期达一个月之久,并且酵母胞壁多糖对PAL活性的诱导效应具有可传导性。     

黄瓜不同品种苗期感染枯萎病菌后几种酶活性的变化

分析了黄瓜不同抗性品种受枯萎病菌侵染后,叶片组织内过氧化物酶（POD）、多酚氧化酶（PPO）、苯丙氨酸解氨酶（PAL）和超氧化物歧化酶（SOD）活性的变化。结果表明,无论是抗病品种还是感病品种,在接种枯萎病菌后,随着接种天数的增加,4种酶活性与对照相比均有一定程度的升高,但抗病品种的酶活性增加幅度高于感病品种。说明这4种酶在黄瓜对枯萎病的抗性机制中起了重要作用。     

玉米对镰刀菌茎腐病抗性的生化反应

在抽雄期用禾谷镰刀菌孢子悬浮液接种抗病品种陕单931和感病品种西农11号,于接种后测定茎秆髓部组织内苯丙氨酸解氨酶、过氧化物酶活性变化、木质素和绿原酸的变化。结果表明,玉米植株受镰刀菌侵染后,抗病品种的苯丙氨酸解氨酶酶活上升快,活性强,且形成两个活性高峰,高活性时间持续长;感病品种苯丙氨酸解氨酶酶活上升慢,活性相对较弱,且只形成一个峰,高活性持续时间短。抗病品种过氧化物酶酶活峰值高,感病品种过氧化物酶酶活峰值低,且抗病品种高酶活持续的时间长,感病品种高酶活持续的短。研究还表明,植株原生的木质素对玉米的抗性贡献不大,而诱导的木质素在玉米的抗病性中起着主导作用。同时,无论抗、感品种,其组织诱导提取液对镰刀菌都有一定的抑制作用。     

采前水杨酸处理对甜瓜采后病害及抗性相关酶和防卫物质诱导的研究

采用1.0 mmol/L水杨酸溶液在甜瓜花后2周(幼果期)、花后3周(膨大期)、花后4周(网纹形成期)及采收前48 h(预采期)四个生长期分别进行喷施处理,对照用清水处理,采收预冷后果实于7℃下贮藏,分别对贮藏过程中甜瓜果实的发病率、病情指数、总酚含量、类黄酮含量、木质素含量、苯丙氨酸解氨酶活性、几丁质酶活性、β-1,3-葡聚糖酶活性进行测定。结果表明:与对照相比,1.0 mmol/L水杨酸处理可以明显推迟甜瓜发病时间,降低发病率和病情指数;在贮藏后期,还可使总酚、类黄酮、木质素含量积累高于对照,并诱导甜瓜果实几丁质酶、β-1,3-葡聚糖酶、苯丙氨酸解氨酶的活性升高。因此,在不同的生长期内可以用1.0 mmol/L水杨酸溶液处理,易于保存,可以减少甜瓜腐烂造成的损失,提高营养价值。     

黄瓜不同品种苗期感染枯萎病菌后几种酶活性的变化

分析了黄瓜不同抗性品种受枯萎病菌侵染后,叶片组织内过氧化物酶(POD)、多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)和超氧化物歧化酶(SOD)活性的变化.结果表明,无论是抗病品种还是感病品种,在接种枯萎病菌后,随着接种天数的增加,4种酶活性与对照相比均有一定程度的升高,但抗病品种的酶活性增加幅度高于感病品种.说明这4种酶在黄瓜对枯萎病的抗性机制中起了重要作用.     

Genetics of Resistance to Phytophthora capsici in the Pepper Line 'SCM-334'

In order to establish a genetic model of the resistance to Phytophthora capsici in Capsicum annuum genotype ‘SCM-334’, two experiments were conducted which included ‘SCM-334’, as well as, the susceptible line ‘Morrón INIA 224’ and their Fl, F2, F3 and BC1 generations. We also tried to introgress a recessive gene, hypothetically responsible for resistance to P. capsici, from ‘SCM-334’ into ‘Morrón INIA 224’. Inoculations were made, when plants had 4—6 leaves, by irrigating the culture substrate with a zoospore suspension of P. capsici isolate ‘Bl’. The χ² test was applied to segregating generations to determine how many genes were involved in resistance. The hypothesis which explained the obtained segregations best, although not completely, was one that assumes 3 genes in ‘SCM-334’;, with at least 3 alleles in the heterozygous condition or 4 at any position, present in any genotype in order to be resistant. The influence of the isolate's aggressiveness and the inoculation method on the results are discussed.     

辣椒SRAP-PCR反应体系的建立与优化

SRAP标记(Sequence-related amplified polymorphism,序列相关扩增多态性)是由Li和Quiros发展了一种新的分子标记技术。SRAP标记具有简便、稳定、中等产率、在基因组中分布均匀的特点,已经应用于在水稻、棉花、油菜、马铃薯、苹果、柑橘类果树、樱桃、梅子、大蒜、莴苣及芹菜等植物和水稻稻瘟病的研究中,对开展遗传图谱构建、基因定位与克隆、比较基因组学、cDNA指纹图谱、生物多样性研究、预测杂种优势等研究是一个十分实用的工具。本研究对辣椒SRAP反应体系的程序、模板、Mg^2 等参数进行优化研究,结果表明：辣椒的PCR程序为94℃预变性5min,94℃变性1min,35℃复性1min,72℃延伸1min,5循环,94℃变性1min,50℃复性1min,72℃延伸1min,35循环,最后72℃延伸10min;25μl反应体系中,模板量为15ng,M矿为2．0mmol／L。本研究建立的辣椒SRAP体系重复性好、稳定性强。     

辣椒花药培养再生株群体染色体倍性构成的多样性

采用流式细胞分析术和染色体计数法对辣椒花药培养再生株群体的染色体倍性构成情况进行了鉴定。显示了花药培养再生株中染色体倍性构成的多样性。观察到染色体倍性在不同检测组织器官中的差异现象,说明对同一材料不同器官进行倍性检测以确定植株倍性的必要性,以及植株上部器官的染色体倍性对于结籽能力的决定性。观察到再生株中个别细胞染色体的丢失现象。对流式细胞检测技术和染色体计数法的相关性进行了研究,得出2种检测技术下二者的吻合度为0.95,并对流式检测技术中的偏峰现象进行了初步的分析。     

AFLP Analysis of Mitochondrial DNA from a Cytoplasmic Male Sterility Line and its Maintainer in Pepper （Capsicum annuum L.）

Cytoplasmic male sterility （CMS） is a maternally inherited trait characterized by the inability of a plant to produce functional pollen, which is widespread among higher plants. CMS system is a valuable tool for plant brc, ders to utilize in hybrid seed production and for molecular biologists to study the interaction between nuclear and mitochondrial genomes. Investigations into the molecular mechanism of CMS in several species have revealed that the incompatible nuclear-mitochondrial interactions leading to new chimeric mitochondrial genes such as T-urfl3 for Texas male sterility cytoplasm in maize, pcfin petunia, orf522 in sunflower, orf107 in sorghum and orf244 gene in Brassica may be responsible for CMS （Dewey et al., 1986; 1987; Young and Hanson,1987; Nivison and Hanson, 1989; Kohler et al., 1991; Moneger et al., 1994; Tang et al., 1996; Handa et al., 1995; Singh and Brown, 1991）.     

Effect of Water Stress on the Lipid and Fatty Acid Composition of Sweet Pepper (Capsicum annuum L.)

Sweet pepper ( Capsicum annuum L.) plants were grown under field irrigation and dryland conditions. Stress was imposed 12 d after planting by withholding water for 8 d, and seedlings were harvested for analysis 20 d after planting. In stressed plants, leaf water potential dropped from -0.65 to - 1.03 MPa and water saturation deficit increased by 40 %; plant height did not show a significant reduction. The fresh and dry weights of stressed seedlings and their ratio decreased. The total lipid and total phosphorus contents of stressed seedlings decreased by about 43 % and 71 %, respectively, in comparison to the contents of the watered seedlings. The diacylglycerol, free fatty acid and total polar lipid contents decreased significantly with stress, the last mentioned by more than 50 % in phospholipid levels. Glycolipid levels; were unchanged and the amount of triacylglycerol increase by about 30 % over the control.
Despite the differences found in the fatty acid composition of various lipid classes and between treatments, the degree of unsaturation did not change significantly either in control or stressed seedlings. Under stress conditions, free sterol levels increased without showing any change in the ratio of 'more planar' to 'less planar' sterols. The increase in free sterols and the decrease in phospholipid levels under water deficit conditions raised the sterol/phospholipid molar ratio 3-fold. The different responses of the lipid classes to water deficits and their possible significance are discussed.     

辣椒疫霉菌粗毒素对辣椒种子发芽及幼苗生长特性的影响

辣椒疫霉菌（Phytophthora capsici）可对寄主植物产生致病性的毒素,使辣椒产生类似病原菌侵染引起的症状。将辣椒疫病病原菌粗毒素按10％,20％,30％,40％,50％,60％,70％,80％,90％,100％的体积比浓度,分别作用于未萌发和已萌发的辣椒种子,结果表明,辣椒疫霉菌粗毒素对辣椒种子发芽指数、辣椒幼苗株高、下胚轴长以及辣椒胚根的主根长、侧根长、侧根。数具有明显的抑制作用。通过主、侧根抑制率的比较,在同一浓度下,粗毒素对侧根的抑制作用大于主根。     

Inheritance of resistance to anthracnose (Colletotrichum capsici) at seedling and fruiting stages in chili pepper (Capsicum spp.)

Inheritance of resistance to anthracnose at fruiting and seedling stages was studied in two F₂ populations from a cross between Capsicum annuum cv. ‘Bangchang’ and Capsicum chinense‘PBC932’. The first F₂ was used to study anthracnose resistance at fruiting stage on mature green and ripe red fruit, and the second F₂ was used to study the resistance at both seedling and fruiting stages. Fruit inoculation was performed on detached fruit using a microinjector. Disease severity was assessed on a 0–9 scale at 7 days after inoculation. Seedling inoculation was performed using a drop method on detached leaves of 4‐week‐old seedlings. Disease severity was assessed on a 1–9 scale at 3 days after inoculation. The distribution of the disease scores of green and red fruit, and seedlings in both F₂ populations suggested a single gene model for each trait. Three different recessive genes were responsible for the three resistances from this cross. Linkage analysis suggested that the resistances at green and red fruit were linked (recombination frequency 0.25), and that the seedling resistance was not linked to the fruit resistances.     

Gene action in the resistance of peppers (Capsicum annuum) to Phytophthora stem blight (Phytophthora capsici L.)

Summary The variation among single and three-way crosses derived from seven lines of pepper (Capsicum annuum) selected for resistance to Phytophthora capsici was analyzed into statistical-genetic components due to general and specific combining abilities and additive-by-additive epistasis. Indirect evidence of higher order epistasis was also estimated. Epistasis was a principal source of variation. It was correlated with the level of aggressiveness of the pathogen. A breeding method such as recurrent selection seems to be the most appropriate to improve resistance to the fungus.     

海南高产甜椒杂交制种技术研究

对海南特定气候特点下影响甜椒杂交制种的几个环节进行了详细研究，结果表明：以开花前1d去雄、第2d早上授粉单果饱满种子数最多；摄子去雄、不去花瓣，摄子去雄、去部分花瓣，徒手去雄3种去雄方法对座果率、种子数差异不显著；空气相对湿度大于70%，温度25~30℃花粉发芽率较高；完全转色种果的种子发芽率最高，后熟作用对发芽率影响不大，而始转色果和绿熟果随着后熟时间的增加，发芽率逐渐升高；完熟果种子在常温保存200d后发芽率几乎不变，而绿熟果和始转色果则下降较快。针对上述结果，提出了提高制种纯度和产量的相关方案和措施。