Effect of Shading on the Growth and Yield of Mungbean (Vigna radiata [L.] Wilczek)

Mungbean grown as intercrop suffers shading stress form companion crop at different growth stages. Grain filling stage, which appears to be very much sensitive to light conditions, needs special attention to deal with, in order to maximize the benefit from intercropping systems. Growth and yield response of mungbean to different shading conditions imposed at the onset of pod formation stage was evaluated. Shading nets were used to cut down the incident photosynthetic active rediation by 15 %, 45 % and 75 %. There was almost no difference between the control and 15 % shaded plants for all the parameters studied. Total dry weight was found to decrease with increase in shading intensity and this phenomenon continued till the maturity of the crop. The crop growth rate, relative growth rate and net assimilation rate decreased due to shading. Lower specific leaf weight and higher chlorophyll content were due to increased shading. Decreased photosynthetic active radiation caused significant reduction in pods per plant and thus there was a significant decrease in seed yield per plant. In order to avoid yield loss due to shading at grain filling stage, agronomic manipulation and selection of suitable genotypes are necessary.     

重组近交系群体定位绿豆抗绿豆象基因

绿豆象是对绿豆危害最严重的仓储害虫,检测和利用抗绿豆象基因是控制该害虫最经济有效的方法。利用高感豆象绿豆栽培种Berken和高抗豆象绿豆野生种ACC41亚种内杂交得到的重组近交系（RIL）群体及据此构建的1个包含79个RFLP分子标记的遗传图谱,通过对3个种植环境条件下收获的RIL群体进行2年的室内人工接虫鉴定,评价其抗绿豆象表现。QTL作图结果表明,在第9连锁群mgM213~VrCS161标记之间的1个QTL在2年3点试验中均被检测到,贡献率在74.05%~79.27%,是抗绿豆象主效基因。该QTL的加性效应值为负,表明来自父本ACC41的这个位点的等位基因可以提高绿豆对绿豆象的抗性。本研究结果对开展绿豆抗绿豆象育种以及抗绿豆象基因的精细定位和克隆有重要意义。     

绿豆几个表型性状的遗传特性分析

种皮色泽和花青甙显色是绿豆(Vigna radiata)的重要性状,可在纯度鉴定、辅助选择育种等研究中发挥作用。本研究以绿豆核心种质种皮色泽、花青甙显色性状分析为基础,配制杂交组合,根据不同世代的表型调查,探讨绿豆种皮颜色、光泽和花青甙显色等性状的遗传特征。结果表明,绿种皮对黄种皮为单基因控制,绿色为显性;黑种皮对绿种皮为单基因控制,黑色为显性。绿豆种皮光泽不符合简单性状的遗传规律,且不同组合间后代的表型分布存在差异。绿豆种皮色与光泽间并无连锁关系。植株各部位的花青甙显色对不显色为显性,均符合简单单基因的分离规律。进一步分析表明,不同部位花青甙显色的相关性不一致,其中控制幼茎色基因与控制复叶基部花青甙显色基因紧密连锁在一起,或为一个基因,而控制龙骨瓣花青甙显色的基因与其他相关基因的遗传连锁程度最低。本文对绿豆种皮相关性状及植株花青甙显色性状的遗传分析将为这些性状的育种利用及深入研究奠定基础。     

Understanding the phenylpropanoid pathway for agronomical and nutritional improvement of mungbean

The phenylpropanoid pathway is an important diversified secondary or specialised metabolic route. It gives rise to various metabolites that regulate plant growth, metabolism, and plant–environment interactions. Genetic manipulations of the phenylpropanoid pathway have even improved the agronomy and nutritional status of plants. Irrespective of such explorations, this pathway has not been vastly investigated in legumes to date. Mungbean (Vigna radiata L.) is the most commonly produced leguminous crop of Asia. It is an important source of plant protein that has been recommended over several animal proteins. Dry mungbean seeds as well as sprouts are a rich source of phenylpropanoids. Mungbean sprouts possess increased protein bioavailability and have higher antioxidant potential than dry seeds. The polyphenolic derivatives of the phenylpropanoid pathway in mungbean are responsible for their antioxidant potential. Hence, from this perspective, the present article reviews the agronomic and biochemical traits of mungbean with an emphasis on the phenylpropanoid pathway and derived metabolites.     

Screening of mungbean germplasm against mungbean yellow mosaic India virus and its vector Bemisia tabaci

Yellow mosaic disease (YMD) caused by whitefly (Bemisia tabaci) transmitted mungbean yellow mosaic India virus (MYMIV) is an important constraint of mungbean in Pakistan. One hundred sixty-two mungbean genotypes from eight different geographic regions were evaluated for resistance to MYMIV and its whitefly vector B. tabaci. Resistance levels were assessed by visual scoring of symptoms in the field under natural conditions, in net-house by artificial transmission through whitefly and in greenhouse using graft inoculation for two consecutive years in 2008 and 2009. None of the tested genotypes was found to be disease free, while considerable variation in responses was observed among the genotypes and testing methods. All genotypes were found to be systemically infected in the field. In 2008, 32 genotypes were found to be resistant and 67 were moderately resistant with severity index (SI) values ranging from 1.0 to 1.4 and from 1.5 to 2.4, respectively. In 2009 34 genotypes were found to be resistant and 38 were moderately resistant with the same SI value ranges as in 2008, and the remaining genotypes were moderately susceptible to highly susceptible. However, only 35 genotypes were found to be moderately resistant with SI values of 1.5-2.4 and latent periods (LP) of 17-21 days when evaluated using artificial transmission through whiteflies. Similar results were obtained when these genotypes were evaluated using graft inoculation. Significant differences in adult whitefly densities among tested genotypes were also observed during both years but no correlation between the number of whiteflies and disease severity was observed. The results indicated that these genotypes did not have a high level of resistance against MYMIV, however, they may provide sources of partial resistance which can be exploited in the breeding programmes to develop mungbean genotypes resistant to MYMD or they can be used directly as varieties to manage MYMD after evaluation for acceptable agronomic characteristics, adaptation and stability in various regions.     

Effect of addition of organic residues,farmyard manure and fertilizer nitrogen on soil fertility in rice‐wheat cropping system

A field experiment was conducted for 3 crop years (July‐June) at the Indian Agricultural Research Institute, New Delhi to study the effects of Sesbania and cowpea green manuring (GM) and incorporation of mungbean residues after harvesting grain, Leucaena loppings, FYM and wheat straw incorporation before planting rice and application of 0,40,80 and 120 kg N ha^?1 to rice on the soil organic carbon (SOC), alkaline permanganate oxidizable N (APO‐N), 0.5 M sodium bicarbonate extractable P (SBC‐P) and 1N ammonium acetate exchangeable K (AAE‐K) in surface 0–15 cm soil after the harvest of rice and wheat grown in sequence. Green manuring and addition of organic residues prevented the decline in SOC. On the other hand addition of N fertilizer tended to decrease SOC after rice harvest. On the contrary application of green manures, organic residues, FYM and fertilizer N increased APO‐N, which indicates the benefit of these treatments to a more labile soil organic N pool. Also application of green manures, organic residues, FYM and fertilizer N increased SBC‐P. Not much change was observed in AAE‐K by the treatments applied.     

不同基因型小麦与绿豆冠层冷温现象研究

对小麦与绿豆冠层冷温现象的研究表明,小麦与绿豆冠层冷温现象的显著特征是小麦和绿豆中某些基因型材料冠层温度持续偏低,且不因年份更迭和天气的变化而异,具有很高的稳定性。与植株的冷温相伴随,一些重要生物学性状如叶片功能期、叶绿素和蛋白质N含量、超氧化物歧化酶活性和净光合速率等也较冠层温度持续偏高的基因型材料明显为佳,这为进一步提高产量奠定了坚实的代谢基础。小麦与绿豆的亲缘关系很远,但共同的冷温特性使它们之中的某些基因型材料在一些重要生物学性状上具有相通的特性,且有利于作物生产能力的提高。     

60Co辐射对绿豆主要农艺性状影响及特异突变体创制

辐射诱变是作物育种行之有效的途径之一,但绿豆诱变育种研究相对落后。用300、400、500、600、700Gy 5个剂量的⁶⁰Co辐射处理籽粒大小不同的冀绿10号、冀绿15和V1128 3个品种的干籽粒种子,分析后代出苗率和主要农艺性状的变异情况,并对后代材料进行突变体选择。结果表明,不同辐射剂量⁶⁰Co对不同籽粒大小的绿豆品种有不同的辐射效果,其中,对大、中籽粒品种冀绿10号和冀绿15的出苗有明显的抑制作用,而对小籽粒品种V1128的出苗有明显的促进作用;高剂量辐射对绿豆后代营养体性状中主茎分枝数影响最大,使单株荚数和产量有显著增加的趋势,但对荚长和单荚粒数有一定的抑制作用;通过后代连续选择,获得了无分枝、雄性不育及荚型特异等稳定遗传的变异材料。可为绿豆辐射育种提供理论依据,创新的变异材料可供今后遗传研究及育种利用。     

绿豆白粉病的遗传

本文以白粉病敏感品种UT1和抗性品种组成的5个杂交组合为材料,研究了绿豆白粉病的遗传模式和遗传力。结果表明：UT1为白粉病高敏感品种,VC3528A和VC1560A为高抗品种,VC3890A和VC1482A为抗性品种,而VC3543A为中抗材料;白粉病在3个组合中由单个显性基因控制,但在一个组合中由两个显性基因控制,在组合3中,白粉病为多基因控制,遗传力为40.31%。     

玉米绿豆间作效应分析

[目的]研究绿豆（Phaseolusradiatus）／玉米（ZeamaysL．）间作对玉米、绿豆产量和主要农艺性状的影响,筛选出适宜黑龙江省西部半干旱地区玉米与绿豆的间作模式。[方法]采用田间试验。绿豆／玉米间作比例分别为1：2、2：4、4：2、4：6、6：4、2：1,分别以玉米单作和绿豆单作为对照。[结果]与绿豆和玉米分别单作相比,绿豆／玉米间作模式具有较大的生产潜力,有明显的经济效益优势,当绿豆与玉米的间作比例为6：4时复合群体的总经济效益最高;绿豆与玉米间作,边际效应使玉米的一些农艺性状得到改善,而绿豆的一些性状得到减弱,这是受到负边际效应影响的结果。[结论]黑龙江省西部半干旱地区,绿豆与玉米的间作比例以6：4较适宜。