加拿大蓟天敌─欧洲方喙象的寄主专一性测定

在温度为25～28 ℃的养虫室内选择具有代表性的菊科植物及豆科、禾本科牧草共10科30种植物对欧洲方喙象进行寄主专一性测定试验，结果表明其食性专一，只取食加拿大蓟，个别成虫或幼虫在饥饿状态下仅少量取食菊科其他植物，但随后即拒绝取食。非选择性试验（饥饿试验）表明欧洲方喙象耐饥饿能力强，不同龄期平均达28 d。欧洲方喙象最适宜的生长温度是25 ℃，高于30 ℃或低于10 ℃，生长发育则受到抑制。     

甘薯膨大素对慈菇生长发育的影响

施用甘薯膨胀大素可改善慈菇营养生长状况,促进慈菇球茎的膨大,球茎开始膨大时叶面喷施甘薯膨大素,可显著增加早期产量;定植时及球茎开始膨大时２次施用甘薯膨大素,早期产量增加不显著,总产量显著增加。     

Response of black rot in cabbage to spatial distribution of inoculum

Disease progress of black rot in cabbage crop was studied over three years in field plots to compare the effects of uni-focal and multi-focal inoculum applied in equal amounts per plot. Disease progress (plant incidence and leaf incidence) was plotted over time, three dimensional maps were made, and disease aggregation was studied by means of geostatistics, black-black counts and Moran's I statistic. Black rot progress was primarily due to focus expansion. Secondary foci may appear at short distances from the initial focus but they usually merge with the expanding initial focus. Anisotropy occurred occasionally but was of minor importance. Disease proceeds faster in plots with multi-focal inoculation than in those with uni-focal inoculation. Probably, serious epidemics in Dutch cabbage fields originate from large numbers of foci.     

家蚕产卵量的基因效应参数估计

用产卵量差异较大的两个近交系782和Ekp作亲本,配制了F1、F2正反交及F1与两亲本的回交B1和B2,加上两亲本P1和P2共8个世代,采用多世代平均值的多元回归分析方法对产卵量的基因效应参数进行了估计,得到了如下结果：（1）建立了分析家蚕产卵量的常染色体基因加性、显性和性染色体基因加性效应的非二体遗传模型,并通过实际数据检验表明产卵量遗传符合这个模式;（2）产卵量的遗传主要取决于常染色体上基因加性效应,其次是性染色体基因加性效应,显性效应很小。     

杂交马褂木幼林施肥试验

以杂交马褂木幼林为供试对象，进行不同肥料种类和施肥量试验。结果表明：追肥1a后，各施肥处理间树高生长量有极显著差异，以施洞氮复合肥0.25kg／株和马褂木无机专用肥0.25k∥株的树高生长量最大；追肥3a后，各施肥处理间树高生长量有极显著差异，胸径生长量没有显著差异，以施尿素0.25kg／株的树高生长量最大，胸径和树高生长量分别为3.09em和1.85m，比对照分别提高72％和111％。综合成本效益考虑，适合推广的肥料种类和施肥量依次为马褂木无机专用肥0.1ks／株、马褂木无机专用肥0.25k∥株和尿素0.25kg／株。     

Tissue Culture Response from Seedling Explants of Commercial Barley Cultivars Grown in Bulgaria

Abstract

Only a few studies have been conducted in which regenerability of barley has been examined. In the current study, 17 barley genotypes (nine two-row malting type: Aster, Emon, Ruen, Jubiley, PV101, Körten, Krassi 2, Perun and Igri, and eight six-row feed types: Karnobat, Hemus, Jerun, Veslets, Aheloi 2, Diana, Panagon, and Izrgev) were evaluated for tissue-culture response from seedlings during a three-year period. Regenerable calli were obtained from all tested genotypes. Although there was much variation in regeneration capacity among the cultivars, plants were obtained from all cultivars. The majority of green plants grown to maturity were fertile and normal in appearance. The frequency of embryogénie callus induction and regenerability was influenced by genotype and growth conditions of the donor plants. Genotype was the most important determinant of the in vitro response. The best in vitro performance, based on ability to form regenerable calli and to regenerate plants was observed for Ruen, Aster, and Emon.     

Decomposition of (1–3,1–4)-β-Glucan and Expression of the (1–3,1–4) -β-Glucanase Gene in Rice Stems during Ripening

Abstract

To elucidate the possible participation of hemicellulose decomposition in lodging resistance, we studied the change of hemicellulose and cellulose content in the stems of rice during the ripening stage by methylation analysis and the expression of related genes by Northern blotting. In the rice stem in ripening stage, content of (1-3,1-4)-β-glucan, a component of hemicellulose, decreased markedly although the content of arabinoxylan, a major component of hemicellulose, and cellulose showed little change during the same growth period. On the other hand, expression of the Gns 1 gene, which may encode (1-3,1-4) -β-glucanase that catalyzes the degradation of (1-3,14) -β-glucan, increased sharply in the stem. The mechanism of decomposition of (1-3,1-4) -β-glucan in rice stem and the possible association with lodging resistance is discussed.     

Response of Sorghum to Abiotic Stresses: A Review

Sorghum [(Sorghum bicolor L.) Moench] is a highly productive crop plant, which can be used for alternative energy resource, human food, livestock feed or industrial purposes. The biomass of sorghum can be utilized as solid fuel via thermochemical routes or as a carbohydrate substrate via fermentation processes. The plant has a great adaptation potential to drought, high salinity and high temperature, which are important characteristics of genotypes growing in extreme environments. However, the climate change in the 21st century may bring about new challenges in the cultivated areas. In this review, we summarize the most recent literature about the responses of sorghum to the most important abiotic stresses: nutrient deficiency, aluminium stress, drought, high salinity, waterlogging or temperature stress the plants have to cope with during cultivation. The advanced molecular and system biological tools provide new opportunities for breeders to select stress‐tolerant and high‐yielding cultivars.     

小麦小分子RNA TaMIR1129介导植株抵御低氮逆境功能研究

本研究针对迄今有关小麦小分子RNA(miRNA)家族成员介导植株氮素吸收和利用机理尚少见报道的现状,对TaMIR1129的表达特征和介导植株抵御低氮逆境功能进行了研究。结果表明,TaMIR1129呈低氮胁迫诱导表达,表现为随氮浓度降低(0.02~6mmol/L)和处理时间延长(0~48h)表达水平不断增高特征。此外,低氮诱导的高表达水平在恢复供氮后表达下调。表明该miRNA对介质中氮素应答呈典型的时间及浓度依赖特征。TaMIR1129作用2个靶基因,包括Molybdenum cofactor sulfurase(TaMCS)和Major facilitator family transporter(TaMFFT),上述基因应答低氮特征与TaMIR1129相反。遗传转化结果表明,超表达TaMIR1129具有显著增强植株抵御低氮逆境的能力。表现为与野生型对照相比,转基因系Sen 1和Sen 2低氮处理后植株形态增大,干质量增加,氮累积量增多。表明TaMIR1129与作用靶基因构建miRNA/target模块在介导植株抵御低氮逆境中发挥重要作用。     

Effects of Paclobutrazol on Dry Matter Distribution and Yield in Peanut

Abstract

Paclobutrazol (PB), an inhibitor of endogenous gibberellin synthesis, was applied to peanut plants altered dry-matter distribution and increased seed yield. PB solution at a concentration of 100, 200 or 400 ppm was sprayed on foliage at the beginning of the pod formation stage (BPFS), the early pod filling stage (EPFS) and the middle pod filling stage (MPFS) .The height of the plants treated with PB at BPFS and EPFS was shorter than that of the control plants by more than 10 and 5 cm, respectively. The pod number of the plants treated with 100 or 200 ppm PB at any developmental stage was higher than that of the plants treated with 0 or 400 ppm PB. The seed yield was increased by PB applied at any stage, and the yield after the treatment with 100 or 200 ppm PB at BPFS or EPFS was approximately 370 gm~².