Study on Identification of RAPD Marker of Phytophthora sojae Associated with Rps1-k

A near-isogenic lines(NILs)-Williams and Williams82 is used to identify molecular marker linked to the resistance gene Rps1-k by RAPD. Genomic DNAs extracted from soybean leaves of the NILs were analyzed by RAPDusing 160 different 10-nt random primers. Some specific DNA fragments were amplified from Williams82 with 4 primer(OPF-16, OPB-05, OPD-06 and OPH-05) which contains Rps1-k. All these specific DNA fragments were not de-tected in Williams. The experiment with OPH-05 was repeated 3 times and the results were the same. Using primer-OPH-05 to detect other resistance cultivars with Rps1-k, almost everyone can amplify the specific DNA fragment. So it is inferred that the specific DNA fragment is probably linked to Rps1-k.     

新型缓释甲霜灵颗粒剂对大豆根腐病主要致病菌的防治效果研究

为了能够在大豆整个生育期对大豆根腐病进行防治,试验在2014年采用缓释甲霜灵颗粒剂对大豆根腐病主要致病菌：大豆疫霉病菌、大豆镰孢菌进行了室内菌株菌丝生长抑制试验,同时对缓释甲霜灵颗粒剂在田间持效期及防效进行了田间试验。试验表明：缓释甲霜灵颗粒剂在室内抑菌试验中抑制率最好,对疫霉菌的EC50为0.364,对镰孢菌的EC50为0.5800,均为最小;并且田间试验中发现,在5种防治药剂中防效最好,可以有效防治大豆生长后期大豆根腐病的发病情况,是一种防治大豆根部病害的新型药剂,为绿色、高效的大豆综合防治技术奠定了一定的基础。     

云南魔芋新病害—疫病病原菌的鉴定

\t\t\t\t\t目的\t\t\t\t\t明确烟草疫霉对魔芋的致病性,为其引起的魔芋疫病的防治提供理论基础。\t\t\t\t\t\t\t\t\t\t\t\t\t方法\t\t\t\t\t对分离鉴定的5株烟草疫霉菌,在温室和实验室条件下利用植物活体和离体接种法进行致病性鉴定。\t\t\t\t\t\t\t\t\t\t\t\t\t结果\t\t\t\t\t5株疫霉菌对魔芋均表现出相似的强致病性,发病率达到100%。实验室致病性鉴定表明：疫霉菌株Ps1对叶片(病情指数98.33)和根部(病情指数94.07)致病力显著高于球茎(病情指数78.33)和茎秆(病情指数71.11);在辣椒果实、马铃薯叶片、大豆和烟草茎基部分别接种Ps1菌株,不同寄主均出现明显病斑,其中疫霉菌对马铃薯的致病性(病情指数60.67)最强,对大豆的致病性最弱(病情指数32.59)。\t\t\t\t\t\t\t\t\t\t\t\t\t结论\t\t\t\t\t疫霉菌不仅对魔芋的不同部位有较强的致病性,还可侵染其他植物。\t\t\t\t     

水杨酸诱导辣椒抗疫病生化机制的研究

对水杨酸(SA)处理及其挑战接种辣椒疫霉菌的4个抗性不同的辣椒品系体内木质素含量和多酚氧化酶(PPO)、过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)活性的测定结果表明:SA诱导的供试品系与未经诱导的相同品系相比,木质素含量增高,PPO、POD、PAL活性增强,其中木质素的含量与抗病性呈显著正相关;挑战接种后两者相比,SA处理的供试材料的木质素含量和PPO、POD、PAL活性的增强幅度更大,其中抗、耐病品系的增加早且增加幅度高于感病、高感品系。值得注意的是,经SA诱导的各供试品系接种后木质素含量与抗病性也呈显著相关。木质素含量与相关酶活性的上述变化趋势与SA对各品系的诱抗效果完全吻合。     

Multi-trait selection in a diallel crossing scheme of cocoa

Cocoa breeding seeks to increase the yield by area unit. In this context, one must consider the resistance to Phytophthora disease, the most serious one in cocoa culture. Thus, herein two traits were used: yield, i.e. number of healthy pods obtained in 7 years and Phytophthora resistance, estimated by pod rot rate. A combined individual‐family selection is proposed on the basis of the total genetic value in order to spread clonal material. This selection method was applied in a 6 × 6 diallel scheme in Cameroon. The heritability of Phytophthora resistance (near 0.2) was higher than for yield (0.13). A selection index was constructed to obtain good genetic gains on each of the two traits (yield and Phytophthora resistance). To improve prediction of genetic values, a third trait, potential yield, was used. With the chosen weight, the expected genetic gain was about 35% for resistance at 1% level of selection. This selection was applied and a confirmation trial is being established with the selected trees.     

复合菌剂抑制辣椒疫病的土壤细菌群落特征

根际促生菌能通过调控土壤微生物群落组成及功能有效防控作物土传病害。辣椒疫病是由疫霉菌（Phytophthora capsici）引起的严重土传病害之一,然而,目前针对根际促生菌抑制辣椒疫病的效应及其与土壤微生物群落之间关联的研究欠缺。本研究以长期有机培育的健康土壤为材料,通过平板对峙法,筛选并复配出具有显著拮抗病原菌的复合菌剂,通过盆栽实验探究该复合菌剂对辣椒疫病的防治效应及其微生物群落特征。拮抗实验表明,复合菌剂与单一菌株相比能够显著增加对病原菌的拮抗率。盆栽实验表明,接种复合菌剂与对照（接种辣椒疫霉菌）相比,辣椒疫病的发病率和致死率显著降低了14.3%和23.8%,细菌群落α多样性显著下降,细菌群落组成发生改变,与诱导植物系统抗性的细菌群落双组分系统功能显著增加,其中显著增加的波特氏菌属与土壤中病原菌的数量显著负相关。本研究结果为辣椒实际生产中应用复合菌剂防控辣椒疫病提供了技术支撑。     

栎树猝死病菌国外研究进展

栎树猝死病菌Phytophthora ramorum(Werres,De Cock&Man in’t Veld)是一种危害性极大的病原菌,主要分布于欧美。文中阐述了该病原生物学性状、传播方式、防治措施、对生态环境的影响以及分子生物学和免疫学技术的应用等方面的国外研究进展。     

Improving Potato Production in Kenya, Uganda and Ethiopia: A System Diagnosis

Increased productivity of potatoes can improve the livelihood of smallholder potato farmers in Kenya, Uganda and Ethiopia and is required to meet the growing demand. This paper investigates the opportunities for potato system improvement that could result in improved productivity. Through a diagnosis of the potato systems in the three countries on the basis of surveys and stakeholder workshops, seed potato quality management, bacterial wilt control, late blight control and soil fertility management were identified as key technical intervention topics. For effective problem solving in these areas, the functioning of the potato innovation system requires improvement to better deliver the functions of potato marketing as well as knowledge development and information exchange. With use of a ‘system failure framework’ the shortcomings of the potato innovation system are identified and discussed and options for improvement are suggested.     

麻疫霉对甲霜灵抗性的遗传研究

在实验室条件下研究了苎麻疫霉（ＰｈｙｔｏｐｈｔｈｏｒａｂｏｅｈｍｅｒｉａｅＳａｗａｄａ）对甲霜灵抗性的特点和遗传规律。结果表明：苎麻疫霉易对甲霜灵产生抗性，抗性水平可达野生型亲本的１８００倍以上，但抗性遗传不稳定；抗甲霜灵（Ｍｒｔ）突变株ＥＣ３１的Ｍｒｔ性状在游动孢子后代中发生连续分离，其余突变株的Ｍｒｔ性状经一代单游动孢子分离后完全丧失；Ｍｒｔ单游动孢子株在不含甲霜灵的利马豆培养基（ＬＢＡ）平板上培养１０～１４ｄ后对甲霜灵的抗性下降或丧失，其游动孢子后代中Ｍｒｔ个体比例相应减少；而在含甲霜灵的ＬＢＡ上，Ｍｒｔ单孢株的Ｍｒｔ性状可以保持一个月以上，且随着与甲霜灵接触时间的增加，其游动孢子后代中Ｍｒｔ个体比例有上升趋势。     

辣椒疫霉漆酶基因Pclac3克隆表达

辣椒疫霉是一种侵染性植物病原,能引起多种茄科及葫芦科植物的病害。利用同源克隆法从辣椒疫霉基因组内克隆了漆酶基因Pclac3,该基因全长1 881个核苷酸,编码626个氨基酸,与已知的真菌漆酶基因具有较高的同源性,并且具备漆酶基因的保守区域。利用PCR将该基因克隆于pPIC9K载体,并转化于毕赤酵母GS115,经过1%甲醇诱导表达获得其异源表达产物。将表达产物进行SDS-PAGE检测,获得分子量大约为90 kDa的特异蛋白。利用ABTS法对Pclac3的表达产物粗酶液进行酶活性分析发现,其活性在第11天时最大,达到45 U/mL。这为研究辣椒疫霉漆酶基因家族及探索卵菌漆酶生物活性及其潜在的应用提供了理论依据。