Genetic regulation of conidiation in Trichoderma hamatun

Achieving a balance between vegetative growth and spore production is essential for successful biocontrol by fungi. Low sporulation rates in the field can result in poor establishment and survival,whereas failure of conidia to recognise hosts can lead to persistence without efficacy. Commercial biocontrol products involve bulk preparations of conidia, however considerable variability in conidiation rates exists between biocontrol agents, which can restrict choice of strain for production. The majority of studies on Trichoderma conidiation have focused on the species T. viride and T. atroviride.These species form conidia in response to blue and near-UV light and/or nutrient deprivation and conidiation proceeds in a highly co-ordinated fashion, however relatively little is known on the genetic basis of Trichoderrma conidiation. In addition, whilst photoconidiation appears to be a general response detailed studies in other Trichoderma species are absent. In this study, conidiation in the lesser known biocontrol species T. hamatum is being investigated using a combined morphological and molecular approach. In contrast to T. atroviride, conidiation in response to blue-light was weaker and variable and suggested that additional triggers may be required for the T. hamatum photoresponse. A series of comparative photoconidiation assays are currently being undertaken investigating the effect of inoculum type and abiotic factors on timing and intensity of the response.Results will be discussed in relation to the current knowledge on conidial morphogenesis in Trichoderma. In addition to these morphological assays, a selection of genes implicated in sporulation and the blue-light responses are currently being isolated and characterised from T. hamatum. Two genes, phr1 and cmp1 , which were isolated previously from T. atroviride will be used as early and late markers of gene expression during the photoresponse in T. hamatum in order to define time points for harvesting comparable stage-specific RNA from T. hamatum and T. atroviride. Using degenerate PCR putative sporulation gene orthologues have also been identified in T. hamatum.Work is currently underway to isolate genomic clones of these genes from T. hamatum and T.atroviride. Sequence and expression analysis of orthologues, including expression in response to abiotic factors will be presented and discussed in relation to the current knowledge of the molecular basis of conidiation in Trichoderma and other filamentous fungi.……     

皖麦30晚播高产栽培主要农艺措施数学模型的初步研究

通过采用回归正交旋转组合设计和计算机模拟寻优方案 ,研究了播期、播量、施氮量对晚播小麦产量的综合效益及产量构成因素的变化规律 ,得出在我省淮北地区晚播小麦选用皖麦 30品种 ,单产在 6 75 0kg/hm2 以上的最优农艺组合为 :播期 10月 2 9～ 11月 6日 ,播量 16 3 .5～ 2 19.0kg/hm2 ,底施纯氮 90～ 12 0kg/hm2 ,配合拔节期追施 90kg/hm2 纯氮 ,其最佳产量结构为 5 72 .0万～ 6 2 5 .5万穗 /hm2 ,穗粒数 34.6～ 36粒 ;千粒重 38～ 41g。     

从3种基质分离的木霉种类鉴定

从福建省的食用菌、植物线虫虫体和植物根际土壤中共分离到125个木霉(Trichoderma)菌株,根据形态学特征和培养性状,鉴定出5种木霉,分别是哈茨木霉(T.harzianum)、绿色木霉(T.viride)、康氏木霉(T.koningii)、拟康氏木霉(T.pseudokoningii)和长枝木霉(T.longibrachiatum).植物根际土壤中的优势种为哈茨木霉和绿色木霉;食用菌上的优势种为康氏木霉和拟康氏木霉;植物线虫虫体上的优势种为绿色木霉.     

深绿木霉紫外光诱导耐低温突变菌株的研究

通过紫外光诱变处理获得一种耐低温(10℃)的深绿木霉(Trichodermaaureoviride)突变菌株Tuv-1。该菌株在PDA培养基上连续转接培养5次,具有稳定遗传性。低温下与亲本菌株相比,Tuv-1菌丝生长速率大,对灰霉病菌的拮抗作用明显。     

利用拮抗木霉菌防治立枯病的研究

从吉林、黑龙江、北京、天津等地采集土样28份，经室内分离纯化后得到木霉菌（Trichoderma.spp)菌株60个，以立枯比丝核菌为供试病原菌，通过对峙培养筛选出1株对立枯丝核菌有强拮抗作用的木霉菌菌株，将其孢子悬液对茄苗不同时期进行人工接种测定其对立枯病的防治，结果表明：这种拮抗木霉菌对茄子苗期立枯病人明显的防治效果，子叶期防效达73．3％，真叶期防效达71．34％。     

品种稳定性的意义及其测定方法(综述)

本文介绍了品种稳定性的两个基本概念:一个稳定的基因型在不同的环境条件下必须具有最小的方差(“生物学概念”);以生态效价来度量,一个稳定的基因型必须与环境具有最小的互作(“农艺学概念”)。根据稳定性的两种概念,本文分类介绍了作物育种中常用的几种品种稳定性分析方法、并且对各种稳定性分析方法及其遗传机制进行了讨论。     

番木瓜炭疽病生防木霉菌株的初步筛选

为利用生物防治的方法抑制番木瓜炭疽病,通过测定并综合分析比较各木霉菌株的抗生作用、产孢量、不同培养基下的抑菌率、生长速度以及耐药性,从90株木霉菌株中初步筛选出拮抗番木瓜炭疽菌的优良木霉菌(Trichodermaspp.)T05-049、T8-R、T05-035和T05-044等4株菌株,其产孢量分别为1.42×109、5.45×108、4.16×108、1.38×109;在1.01 mg/L特可多的条件下,均生长良好;该4个菌株在25、20、15和10℃下生长正常,耐温性较好,对炭疽菌(Colletotrichumspp.)的抗生作用分别为3、1、1、5;分别在PDA和番木瓜培养基上于25、20和15℃下培养,木霉对胶孢炭疽菌(C.gleosporioides)的抑制率在57.05%以上,对辣椒炭疽菌(C.capcisi)的抵制率在47.87%以上.     

11种木霉菌对葡萄灰霉病菌的拮抗作用

对采自宁夏14个市县的170份土样及其它材料进行分离,得到96株木霉菌株,采用形态分类方法鉴定出9种木霉菌以及2种未知名菌种,它们分别为哈茨木霉(Trichoderma harzianum)、绿色木霉(T.viride)、长枝木霉(T.longibrachiatum)、康氏木霉(T.koningii)、拟康氏木霉(T.pseudokoningii)、顶孢木霉(T.fertile)、黄绿木霉(T.aureoviride)、深绿木霉(T.atroviride)、钩状木霉(T.hamatum)以及T.sp1和T.sp2。竞争及对峙培养结果表明:11种木霉菌种对葡萄灰霉病菌(BotrytiscinereaPers.)均有不同程度的拮抗作用,尤其前四种木霉菌表现出了很强的竞争优势,在对峙培养中对葡萄灰霉菌的拮抗系数为Ⅰ￣Ⅱ,抑菌率达61.8%￣77.6%。在光学显微镜下可观察到木霉菌或缠绕或穿入葡萄灰霉菌菌丝生长,并发生菌丝断裂、消解以及细胞原生质浓缩等现象。     

哈茨木霉对辣椒生长的影响

 在田间用哈茨木霉(Trichoderma harzianum)制剂处理土壤,栽培辣椒,结果表明:哈茨木霉不但对辣椒疫霉（Phytophthora capsici）和尖镰孢（Fusarium oxysporum）引起的根腐病具有一定的防病作用,而且能促进植株生长,提前开花、挂果,提高产量15％左右。     

绿色木霉TR-8菌株的生物学特性研究

绿色木霉菌TR-8是一株具有生防潜力的拮抗菌。研究发现TR-8菌株在PDA培养基、查彼培养基和基本培养基上均能较好生长,在基本培养基上生长最快,3种培养基对孢子产生影响不大。温度对菌丝生长和孢子产生影响显著,30℃时菌丝生长最快,25℃时产孢量最大。TR-8菌株在pH值2～10范围内均可生长,pH值5～6时菌丝生长最快,pH值为7时孢子产生量最大。光照处理对菌丝生长影响不明显,但可明显促进孢子产生。葡萄糖和麦芽糖为菌丝生长和产孢的最佳碳源。天冬酰胺是菌丝生长和孢子产生的最佳氮源。不同维生素对菌丝生长和孢子产生作用不同,烟酸对菌丝生长最有利。微量元素对菌丝生长有一定的促进作用,Mn有利于孢子产生。镰刀菌的菌丝提取物对TR-8的孢子产生具有促进作用。