Identification and characterization of virulence-related effectors in the cucumber anthracnose fungus Colletotrichum orbiculare

The anthracnose fungus Colletotrichum orbiculare invades hosts and establishes biotrophy, later switching to necrotrophy, together with the secretion of an arsenal of effectors. In this review, we describe current progress in the study of pathogen effectors. We identified three virulence-related effectors in C. orbiculare, and revealed part of the strategy for effector-mediated infection, including suppression of immunity triggered by particular effectors. The virulence-related effectors accumulate in a unique interfacial region between C. orbiculare and cucumbers around the neck of primary biotrophic invasive hyphae. We found that the secretion of effectors toward the interface involves exocytosis and SEC22-dependent ER-Golgi traffic.     

不同施肥量对甜荞主要产量指标的影响

通过对定西地区甜荞不同施肥量下株高、分枝数、产量、降水利用效率等指标的综合比较认为,最佳的施肥量为:施纯N22.5kg/hm2、P2O530.46kg/hm2、K2O65.48kg/hm2,其对应株高73.4cm,分枝数4.4个,产量896.18kg/hm2,降水利用效率5.38kg/(hm2·mm)。     

Determining the spirit yield of wheat varieties and variety mixtures

Four winter wheat varieties and the four possible three-component mixtures derived from them were included in a trial in Scotland. The site produced low grain protein levels and there were significant yield and specific weight differences between varieties. The variety Deben significantly out-yielded the varieties Claire and Riband, both with and without fungicide treatment, but produced grain with significantly lower spirit yield than Claire. Protein contents and thousand corn weights were good predictors of spirit yield in a reference population of wheat samples, but thousand corn weights did not correlate with spirit yield in the trial, as Claire combined small grain with high spirit yield. The relationship between protein and spirit yield was shown to change at lower protein levels and to differ between varieties. Reduction in spirit yield as protein increased was greater in Deben than in a better distilling variety like Consort. A rapid means of predicting spirit yield, based on small-scale measurement of hot water extract and protein content, was devised and a good association between predicted and measured spirit yield was observed in both the reference population and the trial. Mixtures containing cvs. Claire and Deben did not demonstrate the adverse effects on yield and spirit yield observed, respectively, for these varieties, and a mixture comprising cvs. Claire, Consort and Deben significantly out-yielded Claire and gave higher spirit yields than Deben. These benefits, together with the potential yield stability and disease reduction characteristics of wheat mixtures, make them a viable commercial option for distilling.     

Molecular analysis of genetic stability in micropropagated apple rootstock MM106

Random amplified polymorphic DNA (RAPD) markers were used to assess the genetic stability of 10 micropropagated plants regenerated through axillary buds of clonal apple (Malus pumila Mill.) rootstock MM106. Eleven random decamer primers were successfully used to analyse genomic DNA from mother plants and in vitro plant material. A total of 129 scorable fragments were amplified with an average of 11.73 bands per primer. Among them, 99 were monomorphic and 30 were polymorphic with 23.2% polymorphism. Among these 30, 12 were found monomorphic across seven plants and parent. Three plants could be regarded as off-types. Our results show that RAPD markers could be used to detect the genetic similarities and dissimilarities in micropropagated material.     

Identification of QTLs for rice grain size and shape of Iranian cultivars using SSR markers

Grain size is a main component of rice appearance quality. In this study, we performed the SSR mapping of quantitative trait loci (QTLs) controlling grain size (grain length and breadth) and shape (length/breadth ratio) using an F₂ population of a cross between two Iranian cultivars, Domsephid and Gerdeh, comprising of 192 individuals. A linkage map with 88 markers was constructed, which covered 1367.9 cM of the rice genome with an average distance of 18 cM between markers. Interval mapping procedure was used to identify the QTLs controlling three grain traits, and QTLs detected were further confirmed using composite interval mapping. A total of 11 intervals carrying 18 QTLs for three traits were identifed, that included five QTLs for grain length, seven QTLs for grain breadth, and six QTLs for grain shape. A major QTL for grain length was detected on chromosome 3, that explained 19.3% of the phenotypic variation. Two major QTLs for grain breadth were mapped on chromosomes 3 and 8, which explained 34.1% and 20% of the phenotypic variation, respectively. Another two major QTLs were identified for grain shape on chromosomes 3 and 8, which accounted for 27.1% and 20.5% of the phenotypic variance, respectively. The two QTLs that were mapped for grain shape coincided with the major QTLs detected for grain length and grain breadth. Intrestingly, gs2 QTL specific to grain shape was detected on chromosome 2 that explained 15% of the phenotypic variation.     

Quantifying production potentials of winter wheat in the North China Plain

The North China Plain (NCP) is one of the major winter wheat (Triticum aestivum L.) producing areas in China. Current wheat yields in the NCP stabilize around 5 Mg ha⁻¹ while the demand for wheat in China is growing due to the increase in population and the change in diet. Since options for area expansion of winter wheat are limited, the production per unit of area need to be increased. The objective of this study is to quantify the production potential of winter wheat in the NCP taking into account the spatial and temporal variability caused by climate. We use a calibrated crop growth simulation model to quantify wheat yields for potential and water-limited production situations using 40 years of weather data from 32 meteorological stations in the NCP. Simulation results are linked to a Geographic Information System (GIS) facilitating their presentation and contributing to the identification of hotspots for interventions aimed at yield improvements. In the northern part of the NCP, average simulated potential yields of winter wheat go up to 9.7 Mg ha⁻¹, while average water-limited yields only reach 3 Mg ha⁻¹. In the southern part of the NCP, both average potential and water-limited yields are about 7.5 Mg ha⁻¹. Rainfall is the limiting factor to winter wheat yields in the northern part of the NCP, while in the southern part, the joint effect of low radiation and high temperature are major limiting factors. Temporal variation in potential yields throughout the NCP is low in contrast with the temporal variation in water-limited yields, which is especially great in the northern part. The study calls for the collection of location-specific and disaggregated irrigated and rainfed wheat yield statistics in the NCP facilitating the identification of hotspots for improvement of current wheat yields.     

Genetic studies on the powdery mildew resistance of winter barley lines derived from Hordeum spontaneum accessions collected in Israel

The genetics of the powdery mildew resistance of 15 Hordeum spontaneum-derived winter barley lines were studied in testcrosses with selected cultivars carrying the MIa12 and MIa13 resistance alleles, in order to identify the inheritance of the resistance and to test for linkage with the MIa locus on chromosome 1H (5). A total of 27 genes were identified. Only one of these genes (in line 1–12 x Dura) could eventually be allelic to a gene previously identified in H. spontaneum Koch. A monofactorial dominant inheritance was identified in the majority of the lines. Three of the tested lines possessed recessively inherited genes and in one line a dominant and a recessive gene were identified. In respect to the reaction of the lines against European mildew cultures, lines with a bifactorially inherited resistance had a broader resistance spectrum than those with a monofactorial inheritance, while lines carrying recessive factors showed a moderately expressed resistance. In three cases a linkage with the MIa locus was found, while in two further lines a possible allelism to this locus was indicated by the absence of recombinant progeny plants. By using more than two isolates for linkage analysis, it was possible to identify additional genes for mildew resistance, reaching a maximum number of four genes in the same line. In some cases, a different inheritance was observed for the resistance of the same line against different isolates. It was assumed that different genes exist, each being effective against a different isolate.     

灯盏花不定芽无糖生根培养的微环境调控技术研究

 以灯盏花组培不定芽为材料，研究探讨了不同处理组合的无糖组织培养培微环境调控对灯盏花不定芽的生根率的影响。结果表明：在一定CO₂浓度范围内，通过对各处理间差异显著性SSR检验，处理9的灯盏花无糖组培苗生根率最高，长势最好，与其它处理组合比较达到显著水平。     

36份不同居群半夏同工酶研究*

 采用聚丙烯酰胺凝胶不连续垂直板电泳系统,测定了36份不同居群半夏的过氧化物酶(POD)、酯酶(EST)及苹果酸脱氢酶(MDH)同工酶酶谱。结果表明：所有供试材料在3个同工酶系统中均有半夏物种的共同特征谱带,同时又蕴涵着丰富的多态性。POD酶、EST酶酶谱存在明显差异,酶带数分别为20和24条。采用 DPS数据分析软件对这两类酶带谱进行聚类分析,该结果能够对供试材料的细胞学研究给予合理解释。     

不同烟草品种对云南烟草野火病菌的抗性鉴定*

 采用采自云南省不同地点、不同生理小种的24株烟草野火病菌对24个不同烟草品种及两个野生种黄花烟和长花烟进行抗病性鉴定分析。结果表明,不同抗性品种对不同生理小种的抗性反应差异显著,根据接种后不同烟草品种的形成的病斑直径,将其划分为4个等级：高抗、中抗、中感、高感。辽烟15,G28对于烟草野火病菌0,1号生理小种均表现为高感,而云南省大面积栽培的K326、红花大金元、云烟87等对于两个生理小种均表现为中感,而两个野生种黄花烟和长花烟均表现为高抗,可以作为烟草野火病抗性育种优先利用的种质资源。