魔芋软腐病菌的分离鉴定及其 GFP 标记

为了解贵州魔芋软腐病的致病病原,对取自贵州台江县的魔芋软腐病病原菌进行了分离、回接和鉴定。结果表明：在分离到的16个菌株中发现1株病原菌能引起魔芋软腐病,通过16S rDNA 序列分析发现该病原菌为菊欧文氏杆菌（Erwinia chrysanthemi ）;通过化学转化法,成功获得了病原菌绿色荧光蛋白标记的工程菌株。     

渥丹百合农艺性状及活性成分对钾元素的响应

为探明钾素与渥丹百合生长发育及鳞茎活性成分积累的关系,采用Hoagland营养液浇灌技术,研究不同钾水平(K0、K1、K2、K3、K4)对渥丹百合株高、茎粗、叶片数、叶绿素含量的影响,采用分光光度法、火焰光度法测定并分析了鳞茎中活性物质(多糖、总酚、总黄酮、皂苷)及钾含量的积累.结果表明:1)渥丹百合农艺性状对钾水平的...     

稻虾共作模式下克氏原螯虾对水稻土团聚体特征及有机碳分布的影响

为研究长期稻虾共作模式下克氏原螯虾对水稻土团聚体数量、稳定性以及土壤团聚体有机碳含量、分布的影响,本研究依托始于2014年的长期定位试验,设置冬泡无秸秆还田（W）、冬泡+秸秆还田（WS）和冬泡+秸秆还田+养虾（WSC）3个处理,采集各处理表层土壤样品,分析土壤团聚体及有机碳分布特征。结果表明：土壤水稳性团聚体以>1～2 mm粒级为主,在冬泡条件下秸秆还田处理显著提高了土壤中>2 mm团聚体比例、有机碳含量和有机碳贡献率,且增加了土壤团聚体平均质量直径;相对于冬泡+秸秆还田处理,冬泡+秸秆还田+养虾处理土壤>2 mm和>1～2 mm团聚体比例显著提高了19.8%和6.5%,而0.053～0.25 mm团聚体比例则显著下降了9.2%,且>0.25 mm的团聚体数量、平均质量直径和几何平均直径分别提高了7.8%、20.6%和37.5%。冬泡+秸秆还田+养虾处理的土壤总有机碳、微生物量碳和颗粒有机碳含量较冬泡+秸秆还田处理分别显著提高了6.2%、34.0%和23.1%,且显著提高了<0.25 mm团聚体中有机碳的含量。研究表明,稻虾共作模式下克氏原螯虾养殖促...     

草铵膦对棉花根系发育影响及其生理机制

草铵膦（Phosphinothricin,PPT）在生产上使用后易在土壤中残留,但其对根系生长发育的影响国内尚无报道。本研究在温室内水培条件下用不同浓度PPT处理棉花幼苗根系,研究PPT对棉花根系发育的影响及其生理机制。结果表明,当PPT浓度为1 mg?L-1时,植株根系的总长度、面积和体积显著减小,随着PPT浓度的上升,棉花根系的总表面积、根长和体积的受抑制程度增大,当处理浓度大于5 mg?L-1时,根系的总表面积、根长和体积的受抑制程度达到最大。随着PPT处理浓度的增加,谷氨酰胺合成酶（glutamine synthetase,GS）的活力也显著下降,从而导致铵积累,这可能是草铵膦抑制根系的生长的重要原因。     

过瘤胃胆碱和有机铬对围产期奶牛干物质采食量、奶产量及血液生化指标的影响

本试验旨在研究饲粮中添加过瘤胃胆碱和有机铬对围产期奶牛干物质采食量(DMI)、奶产量及血液生化指标的影响.选取40头健康、经产(平均胎次1～2胎)的中国荷斯坦奶牛,随机分为4组,每组10头牛.对照组饲喂基础饲粮,胆碱组饲喂基础饲粮+30 g/d过瘤胃胆碱,有机铬组饲喂基础饲粮+8g/d蛋氨酸铬,混合组饲喂基础饲粮+30...     

The Adaptive Planting and the Prospect of Industrial Development of Quinoa in China

Quinoa is the only single plant meeting the basic nutritional needs of the human body. It is the whole nutritious food with nutritional balance, wide adaptability, strong resistance and other characteristics. In this paper, the botanical characteristics and nutritional value of quinoa were systematically introduced, and the development of quinoa in China was reviewed. The problems of domestic quinoa industry, the shortage of germplasm resources, the lack of innovation and high-yielding cultivation techniques were analyzed. To provide theoretical references for quinoa planting and industrial development in China, the countermeasures to improve the investment of quinoa industry and promote the development of multi-form industry were put forward.     

番茄细菌性斑点病菌无毒基因研究进展

番茄细菌性斑点病是影响番茄产量和品质的重要病害,Pseudomonas syringaepv.tomato(Pst)为其病原菌,其与番茄的互作系统是研究植物抗感病机理的典型模式系统。Pst存在2种无毒基因:avrPto和avrPtoB,它们编码的蛋白质均能与番茄抗性基因Pto编码的Ser-Thr蛋白激酶互作,符合Flor"基因对基因"学说。AvrPto和AvrPtoB在表达Pto的抗性植物中,与Pto互作,表现无毒功能,引发植物防御反应;而在缺失Pto的感病植物中,它们具有毒性,促进细菌的生长。本文综述了番茄细菌性斑点病菌无毒基因avrPto及avrPtoB的结构特点及其功能,这有助于了解病原物与植物的互作机制,对认识植物的感病性、抗病性以及植物防御反应都具有重要意义。     

Kernel number as a positive target trait for prediction of hybrid performance under low-nitrogen stress as revealed by diallel analysis under contrasting nitrogen conditions

Environmental sustainability concerns make improving yield under lower N input a desirable breeding goal. To evaluate genetic variation and heterosis for low-N tolerance breeding, 28 F1 hybrids from a diallel scheme, along with their eight parental lines, were tested for agronomic traits including kernel number per ear (KNE) and grain yield per plant (GY), in replicated plots over two years under low-nitrogen (LN, without nitrogen application) and normal-nitrogen (NN, 220 kg N ha⁻¹) conditions. Taken together the heritability in this and our previous studies, the correlation with grain yield, and the sensitivity to the stress for target trait selection, KNE was a good secondary target trait for LN selection in maize breeding. KNE also showed much higher mid-parent heterosis than hundred-kernel weight under both nitrogen levels, particularly under LN, indicating that KNE contributed the majority of GY heterosis, particularly under LN. Therefore, KNE can be used as a positive target trait for hybrid performance prediction in LN tolerance breeding. Our results also suggest that breeding hybrids for LN tolerance largely relies on phenotypic evaluation of hybrids under LN condition and yield under LN might be improved more by selection for KNE than by direct selection for GY per se.     

甜瓜雌雄异花同株近等基因系的构建及近等性评价

雌雄异花同株类型在甜瓜杂交制种时可部分免除人工去雄,确保杂交种纯度,所以,对杂种优势利用中有着重要价值.为了研究和利用控制甜瓜雌雄异花同株基因A,用雌雄异花同株材料Mr作母本P1,雄花两性花材料Mm作父本P2,用P1做轮回亲本与F1杂交,经连续回交并最终自交纯化,获得雌雄异花同株近等基因系(BC6F4).用形态相似法和AFLP标记对获得的近等基因系和轮回亲本进行分析,结果表明:(1)Mr xMm的F2与BC6S1分离群体中,雌雄异花同株株数与雄花两性花株数符合3:1比例,回交群体中雌雄异花同株株数和雄花两性花株数符合1:1的比例;在发育期、果皮色、网纹等农艺性状上没有明显差异;(2)用448对AFLP引物检测轮回亲本和近等基因系之间多态性,有417对引物没有多态性,31对有多态性,统计得其遗传相似系数为99.73%;(3)平均每个AFLP引物对可扩增出46.8条带,说明AFLP揭示的遗传信息量很高,是一种评价近等性较理想的分子标记,这与以往结果一致.