银杏茎腐病的防治

介绍了防治银杏腐病Macrophomina phaseoli的方法。采用种子、土壤消毒，适时播种，遮荫保护，喷洒50％退菌特wp600倍、50％多菌灵wp800倍、70％甲基托布津wp1000倍液等措施可减轻该病的危害，使苗木存活率在90％以上。     

芝麻苗期抗茎点枯病鉴定技术研究

研究通过组织分离法从河南省芝麻主产区分离到5 株病原菌,并进一步进行回接鉴定和分子鉴定;通过比较不同消毒剂和消毒时间优化芝麻种子消毒技术;采用最佳消毒技术消毒芝麻种子,在MS培养基上培养无菌苗;5 株病原菌通过菌饼法对12 份芝麻种质资源无菌苗进行抗性鉴定。为芝麻直接生产应用筛选抗性品种,为抗病育种发掘抗性资源。结果表明,5 株病原菌均为芝麻茎点枯病病原菌菜豆壳球孢（Macrophomina phaseolina）;用2% NaClO消毒20 min,获得芝麻无菌苗的效果最好;菌饼法鉴定无菌苗苗期抗性,12 份资源对5 株M.phaseolina 的反应型均不同,只有ZZM0905 和ZZM1205 对5 株病原菌均表现抗病,并且抗性比较稳定。     

桑树内生真菌Macrophomina phaseolina MOD-1产油脂培养基及摇瓶发酵条件的优化试验

从健康桑树根系中分离筛选得到一株内生产油脂真菌——菜豆壳球孢菌MOD-1(Macrophomina phaseolina,MOD-1)。结合均匀设计和单因子筛选法得到该菌株产油脂发酵培养基最优配方为:可溶性淀粉105 g/L,蛋白胨1.1 g/L,磷酸二氢钾1.5 g/L,硫酸铵0.3 g/L,硫酸镁0.32 g/L,氯化锰4.9 nmol/L。在此基础上优化该菌株产油脂的摇瓶发酵条件为:发酵液初始pH7.0,发酵温度26℃,摇瓶转速190 r/min,装液量100 mL。在优化后的培养基组分及摇瓶发酵条件下培养6 d,菌体生长量(干质量)高达41.852 g/L,油脂产量达到25.511 g/L。利用气相色谱-质谱法分别测定菌株在优化后的培养基或发酵条件下产生油脂的脂肪酸组成,前一种条件下检测出9种脂肪酸成分,其中单不饱和脂肪酸含量为67.92%;后一种条件下检测出7种脂肪酸成分,其中单不饱和脂肪酸含量为74.32%。结果表明,在优化培养基及摇瓶发酵条件下,MOD-1菌株的油脂产量增高,组成简单,易于纯化,且单不饱和脂肪酸含量较高。     

芝麻种质资源茎点枯病抗性鉴定研究

对52份芝麻种质资源的茎点枯病抗性进行了鉴定,结果显示:(1)52份供试种质感病严重,病株率39.05%¹00%,平均87.04%,病情指数为0.30100%,平均87.04%,病情指数为0.30¹.00,平均0.82,没有发现免疫资源;(2)聚类分析表明,感病种质37份,占参试材料的71.15%,抗病种质15份,占28.85%;(3)参试材料中地方种质茎点枯病抗性要优于改良品种(系),且种质间的差异较大;(4)本研究鉴定出来的青麻、丰城白芝麻、赣芝9号等15份抗茎点枯病种质可以在芝麻育种及其抗性改良中加以利用。     

茎点枯病菌诱导下芝麻内参基因的筛选

用CodeHop方法设计简并引物克隆得到了GAPDH、β-actin、α-tubulin、UBQ5、RPL4、eIF4A和eEF1α 7个看家基因的部分序列,将这7个基因和GenBank中已公布的18S rRNA、NADHD 2个基因共9个基因作为候选内参基因,利用实时荧光定量PCR技术,分析其在茎点枯病菌诱导下芝麻中的表达稳定性。经BestKeeper、NormFinder和GeNorm软件分析可知,UBQ5、eIF4A、α-tubulin 3个基因表达均较稳定,eEF1α变化最大。当使用多基因作为内参基因时,选择这3个最稳定的候选内参基因即可准确矫正定量结果。     

桉树扦插苗茎腐病防治试验

桉树苗茎腐病主要发生在桉树插穗扦插后10 d期间,且不同无性系间发病率存在明显差别。防治结果表明:在桉树扦插苗发育期间,用50%DGL可湿性粉剂、53.8%KCD干悬浮剂、80%DSX可湿性粉剂、75%BGC可湿性粉剂和40%D.L悬浮剂喷雾,每隔10 d 1次,连续用药4次,能够防治茎腐病的发生与危害,5种供试药剂的防治效果均达到82%~86%,防治的成本很低,仅为4.5元/万株苗。     

芝麻NBS类抗茎点枯病相关基因的克隆与分析

根据前期获得的芝麻抗茎点枯病NBS RGAs序列与河南省芝麻研究中心提供的EST 序列比对结果,设计4对特异引物,从10个对茎点枯病表现不同抗性的芝麻品种中扩增得到16条RGAs（抗病基因同源序列）,GenBank登录号分别为KC477692～KC477707,它们编码的氨基酸序列均具有NBS （核苷酸结合位点）类型抗病基因的特征结构域。Blastx分析结果表明,16个RGAs基因编码的部分氨基酸序列与已知 NBS类抗病蛋白同源性为35％～52％。聚类分析发现这些RGAs基因聚为4类,且均为non TIR NBS类型,为进一步筛选芝麻抗茎点枯病基因奠定了基础。     

冬枣浆胞病病原菌鉴定及其防治研究

近年来冬枣上发生的一种引起枣果浆烂的病害,在山东省冬枣主产区为害很大。病原菌分离和致病性测定结果表明,该病主要由菜豆壳球孢菌[Macrophomina phaseolina (Tassio) Goidanich]侵染所致。经散射光诱导7~10 d,在室内PDA培养基和接种的枣果上可产生分生孢子器。菌丝生长的最适温度为25~32℃,最适pH5.5~8.0。室内测定结果表明,25%凯润EC、60%百泰WG、25%阿米西达SC和50%翠贝DF等4种药剂对菜豆壳球孢菌的抑制中浓度(EC₅₀)分别为0.1970、0.5770、4.4042和55.3120 μg/mL。田间试验表明,50%翠贝DF 330 mg/L或25%凯润EC 250 mg/L 或60%百泰WG 500 mg/L喷雾,防治效果可达88.51％~97.60％。     

Effect of heavy metals on growth and survival of Macrophomina phaseolina (Tassi) Goid.

Summary The effects of Cd, Co, Ni and Zn on growth and survival of Macrophomina phaseolina were studied in vitro. Cd, Ni and Co at 500 g ml^–1 inhibited growth by 78.8%, 73.6% and 11.8%, respectively, after 4 days at 25 ± 1°C. The mycelial dry weight yield was enhanced by 2.1% at 100 g ml^–1 Zn. The population of the pathogen declined in soil amended separately with Cd, Co, Ni and Zn. Cd (4000 mg kg^–1) proved to be the most toxic, by completely inhibiting the survival of the pathogen in soil after 20 days.     

Breeding beans for resistance to terminal drought in the Lowland tropics

In the lowland regions of Latin America, a large proportion of beans are sown at the beginning of a dry season where a guaranteed terminal (end-of-season) drought will reduce yields. This study was undertaken to identify lines within two black bean recombinant inbred line (RIL) populations with resistance to terminal drought. The two RIL populations were developed from crosses between a drought resistant line, B98311 from Michigan, with TLP 19 and VAX 5, two lines from CIAT with improved disease resistance and adaptation to growing conditions in Latin America. The RIL populations were evaluated in experiments conducted in Zamorano, Honduras and Veracruz, Mexico under drought stress and well-watered (non-stress) treatments. Yields were reduced in each experiment by drought and the fungal pathogen, Macrophomina phaseolina. Drought stress, disease pressure and low yields contributed to high coefficients of variation (CV), which made it difficult to select superior lines. Selection was based on rank of geometric mean (GM) yield calculated from the yield in the stress and non-stress treatments. One RIL, L88-63 ranked first in GM yield at both locations. Subsequent testing in Honduras and Michigan confirmed the high yield potential and broad adaptation of L88-63. Breeding beans for drought resistance in lowland tropical environments should also include breeding for resistance to M. phaseolina. This revised version was published online in July 2006 with corrections to the Cover Date.