川西茶区茶黑刺粉虱的田间消长动态

为掌握黑刺粉虱在川西地区茶园的发生动态,为其绿色防控打下基础,通过7年田间调查,系统研究黑刺粉虱的空间分布,卵、各龄幼虫(共3龄)、蛹和成虫的田间消长动态。结果表明:黑刺粉虱主要分布于茶棚中下层,约占虫口总数的90%,其中约70%的虫口分布于茶棚下部;川西茶区黑刺粉虱1年发生3~4代,主要以2~3龄幼虫越冬,越冬存活率约20%;黑刺粉虱在叶层厚且郁闭的茶园发生较重。     

香蕉 - 尖孢镰刀菌互作机理及抗病育种研究进展

由土壤真菌 Fusarium oxysporum f. sp. cubense（Foc）引起的香蕉镰刀菌枯萎病是全世界范围内严重威胁香蕉生产的毁灭性病害。目前已发现 Foc 的 4 个生理小种。20 世纪 70 年代,Foc 1 号生理小种造成我国华南地区的龙牙蕉和粉蕉种植园大面积发病;90 年代中后期,在广东省的香牙蕉种植园发现 Foc 4 号生理小种,并且迅速向其他香蕉产区蔓延。目前,国内各香蕉主产区均有报道发生 Foc 4 号生理小种引起的香蕉枯萎病,该病已成为制约我国香蕉生产的最主要因素。对香蕉枯萎病菌侵染过程以及香蕉枯萎病致病机理、抗性机制、抗病品种选育、抗性种质筛选及抗病性鉴定、防治等多个领域取得的研究进展进行了概述,并对今后研究方向进行了展望,主要包括：（1）在继续研究已有抗病品种对 Foc TR4 抗性的同时,要进一步深入研究 Cavendish 对Foc 1 号生理小种的抗性;（2）利用已经建立的香蕉 CRISPR/Cas9 基因编辑技术体系,获得香蕉枯萎病抗病品种,并进一步应用寄主植物诱导的基因沉默技术（HIGS）获得更加持久稳定的抗病性;（3）将已经建立的香蕉试管苗离体水培系统应用于香蕉-Foc 互作研究。     

培养基营养条件对瓠瓜枯萎病菌的影响(英文)

[目的]研究不同培养条件对瓠瓜枯萎病菌的影响。[方法]在鉴定了安徽省瓠瓜枯萎病菌病原物的基础上,进一步研究了不同培养基和营养条件对该病原菌的生长速率及产孢量的影响。[结果]瓠瓜枯萎病菌在不同培养条件下的生长速率和产孢量明显不同。PDA培养基最适合该病原菌的生长,产孢量以其最高;在麦芽糖为碳源或蛋白胨为氮源的培养基上该病原菌生长最快,产孢量最高。[结论]该研究为丰富瓠瓜枯萎病菌生物学提供了实验依据,并为瓠瓜枯萎病的研究及防治提供了理论基础。     

粒毛盘菌多糖脱蛋白方法及其条件优化

分别采用Sevage法、三氯乙酸-正丁醇(TCA-NBA)法、酶-Sevage法以及酶-TCA-NBA法对粒毛盘菌YM281胞外多糖进行脱蛋白。结果表明:用酶-TCA-NBA法对粒毛盘菌YM281胞外多糖脱蛋白的效果最佳,蛋白脱除率为51.57%,且此时多糖损失率(3.46%)为最低;进一步采用均匀设计优化该方法的脱蛋白条件,所得最优脱蛋白条件为:粒毛盘菌YM281多糖溶液20mL、木瓜蛋白酶溶液11mL、温度42.2℃、pH 4、酶解时间3.5h;除去变性蛋白后,再利用TCA-NBA法脱蛋白2次即可;采用所得的最优方法和条件脱蛋白,其蛋白脱除率高达72.3%,多糖损失率仅为2.93%。     

Rapid Mining of Novel α-Glucosidase and Lipase Inhibitors from Streptomyces sp. HO1518 Using UPLC-QTOF-MS/MS

A rapid and sensitive method using ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS) was applied for the analysis of the metabolic profile of acarviostatin-containing aminooligosaccharides derived from Streptomyces sp. HO1518. A total of ninety-eight aminooligosaccharides, including eighty potential new compounds, were detected mainly based on the characteristic fragment ions originating from quinovosidic bond cleavages in their molecules. Following an LC-MS-guided separation technique, seven new aminooligosaccharides (10–16) along with four known related compounds (17–20) were obtained directly from the crude extract of strain HO1518. Compounds 10–13 represent the first examples of aminooligosaccharides with a rare acarviostatin II02-type structure. In addition, all isolates displayed considerable inhibitory effects on three digestive enzymes, which revealed that the number of the pseudo-trisaccharide core(s), the feasible length of the oligosaccharides, and acyl side chain exerted a crucial influence on their bioactivities. These results demonstrated that the UPLC-QTOF-MS/MS-based metabolomics approach could be applied for the rapid identification of aminooligosaccharides and other similar structures in complex samples. Furthermore, this study highlights the potential of acylated aminooligosaccharides with conspicuous α-glucosidase and lipase inhibition for the future development of multi-target anti-diabetic drugs.     

印度Leh地区沙棘籽油中脂肪酸测定

本文分析了印度Leh地区沙棘籽油中脂肪酸各成分的含量,结果显示沙棘种子含油量为17.61%,籽油富含油酸(23.012%)和亚油酸(30.162%).     

向川安瘿蜂和寄生性长尾小蜂共生菌Wolbachia的检测

Wolbachia是一类胞质遗传共生菌，能调控被其感染宿主的生殖方式。以向川安瘿蜂虫瘿中获得的向川安瘿蜂和其寄生的长尾小蜂为材料，使用Wolbachia的wsp基因特异引物，通过PCR扩增向川安瘿蜂和长尾小蜂Wolbachia的wsp特异片段，以邻位相连法构建Wolbachia的wsp基因的分子系统树。结果表明：向川安瘿蜂和长尾小蜂均感染了Wolbachia；因二者感染Wolbacia的株系Wa和Wb的wsp序列差异大，不能认定在寄生的长尾小蜂和宿主向川安瘿蜂间存在Wolbachia的水平传播。     

EFFECTS OF pH ON GROWTH AND NODULATION OF TWO FORAGE LEGUMES

A study was conducted to compare the responses to acid pH of Medicago sativa and Lotus glaber, two forage legumes with different environmental requirements, either supplied with inorganic nitrogen (N) or inoculated with different strains of their nodule bacteria. Medicago sativa showed, in both treatments, a significant reduction in total dry weight at pH below 6.0. In contrast, Lotus glaber grew equally well at all the pHs assayed in the presence of adequate N. Under inoculated conditions, in the absence of N supply, plant growth was dependent on the bacterial strain used. When the ability of each strain to multiply in culture medium was examined, it was observed that Sinorhizobium meliloti strains showed a pH-sensitive response that inhibited growth at pH 4.0, whereas Mesorhizobium loti strains showed normal growth at this pH. These results suggest that for the effectiveness of Mesorhizobium loti–Lotus glaber symbiosis in acid soils the major factor to be considered is the tolerance of the bacterial strain to acid conditions, while the limiting factors for the Sinorhizobium meliloti–Medicago sativa symbiosis are the sensitivity to low pH of both the plant and its bacteria.     

Screening of field performance of entomopathogenic fungi and nematodes against cabbage root flies (Delia radicum l. and d. floralis (fall.); Diptera,Anthomyiidae)

Finnish isolates of Beauveria bassiana (8 isolates), Metarhizium anisopliae (7), Tolypocladium sp. (2), Paecilomyces farinosus (2), P. fumosoroseus (1), Steinernema feltiae (3) and Bacillus thuringiensis ('Muscabac') were tested for efficacy against mixed populations of Delia radicum and D. floralis under field conditions in 1986–90. All pathogens were applied preventatively, the fungi as aqueous conidial or mycelial suspensions, dry conidia or dry mycelial powder. In only two of the nine experiments did B. bassiana or M. anisopliae give some control. In 1986, B. bassiana SF85–2 and Tolypocladium sp. SF85–4 (both at rate 1.2 x 10⁹ conidia plant‐ 1), and ‘Muscabac’ (25 g 1^?1, 1 dl plant^?1) reduced the number of pupae by 80%, 60% and 50%, respectively, as compared with untreated and chemical (isophenphos) controls. In 1990, M. anisopliae SF86–39 at rate 1.6 x 10⁹conidia plant^?1 and 1.5 x 10⁸ CFU plant^?1 and S. feltiae SFS‐22 (35000 plant^?1), increased the yield of cauliflower 2.2, 1.8, and 2.3‐fold, respectively, as compared with the untreated control, but these yields were only 19%, 15% and 19% of those of the chemical (diazinon) control. Paecilomyces isolates were ineffective in the 1986 experiment in which they were included. Our results suggest that it is difficult to find efficient control agents among the fungal and nematode species tested for use as biopesticides against cabbage root flies, but that the potential of M. anisopliae against these pests deserves further study.     

Occurrence of a new leaf spot disease ofMusa sp. incited byThanatephorus cucumeris

A new leaf spot disease of banana(Musa sp.) cv. ‘Rasthali’ (syn. Silk) was observed in Tamil Nadu, in 1987. The causal organism was isolated in pure culture and identified asRhizoctonia solarii Kühn. The teleomorphic stage,Thanatephorus cucumeris (Frank) Donk, has also been induced artificially. This is the first record of this pathogen causing leaf spot disease onMusa sp. The pathogenicity of basidiospores on several other important crops was also tested.