Deferred Seeding of Blackgram (Phaseolus mungo L.) in Rice (Oryza sativa L.) Field on Yield Advantages and Smothering of Weeds

Field experiments were conducted at Agricultural Experimental Farm, Giridih, Jharkhand, during the kharif (wet) seasons of consecutive four years (1998–2001) to study the effect of staggered seeding of blackgram (Phaseolus mungo L.) in rice field as a cereal–legume intercropping system and to minimize the degree of competition between the crop species to avoid yield damage, and at the same time to create a high level of competition by the intercrops to suppress the weeds. Intercropping systems were assessed on the basis of land equivalent ratio, relative crowding coefficient, aggressivity, actual yield loss, monetary advantage, etc. Intercropping reduced the yield of component crops when compared with respective pure stands. However, deferred seeding of blackgram in rice (30 cm) after one weeding was most remunerative system and registered maximum rice-equivalent yield (2711 kg ha⁻¹). Rice–blackgram (20 cm) intercropping system was very effective for weed smothering among unweeded intercropping treatments. In conclusion, deferred seeding of blackgram in rice field (30 cm) with one weeding may be recommended for better yield, weed suppression and better economics in the eastern plateau region of India.     

Optimisation of a highly efficient shoot regeneration system using leaf explants of Chinese jujube (Ziziphus jujuba Mill.) by response surface methodology

Chinese jujube (Ziziphus jujuba Mill.) is a major fruit crop in Asia. In this study, response surface methodology (RSM) was successfully employed to establish a highly efficient in vitro propagation and regeneration system for the ‘Teapot’ jujube via shoot organogenesis. Among the tested factors, gibberellic acid (GA₃) concentration showed the most significant positive effect. The pre-culture darkness timing and medium were also important factors for highly efficient shoot regeneration of the ‘Teapot’ jujube. The highest regeneration (> 75%) was achieved by 1 week in darkness and culture on wood plant medium (WPM) containing 0.25 mg·L^?1 GA₃, 0.5 mg·L^?1 6-benzylaminopurine (BAP) and 0.1 mg·L^?1 3-indoleacetic acid (IAA). In vitro-derived shoots rooted very well in the modified ¹/₂ Murashige and Skoog (MS) medium containing 0.4 mg·L^?1 3-indolebutyric acid (IBA), resulting in a 100% rooting rate. These findings suggest that the RSM can be employed to optimise the protocols needed for successful in vitro plant regeneration of jujube cultivars, with potential applications in plant genetic transformation practices, polyploidy induction and germplasm preservation.     

草莓茎尖培养快繁技术研究

以童子一号草莓为试材,对草莓葡匐茎茎尖进行组织培养,筛选出低成本下草莓诱导分化培养基、继代增殖培养基分别为:MS BA 0.5 mg/L、MS BA 0.5 mg/L,瓶外生根最佳生长调节剂浓度为IBA 800 mg/L,在温度20～30℃、光强为4 000～10 000 lx、湿度为85%～95%时,组培苗生根性状良好.此方法繁殖的无毒苗,移栽成活率可达99%,每株成本也下降了75%.     

The Eurasian Steppe is an important goat propagation route: A phylogeographic analysis using mitochondrial DNA and Y‐chromosome sequences of Kazakhstani goats

Goats (Capra hircus) were domesticated in the Fertile Crescent and propagated all over the world. The Silk Road through the Eurasian Steppe belt is a possible propagation route for domestic goats to Central Asia. Kazakhstan is in close geographical proximity to domestication centers and covers the majority of the Eurasian Steppe belt. In this study, we examined the genetic diversity and phylogeographic structure of Kazakhstani goats. The mtDNA sequences of 141 Kazakhstani goats were categorized into haplogroups A, C, and D, of which haplogroup A was predominant (97%), whereas haplogroups C and D were detected at low frequencies (1.4% each). The Kazakhstani haplotypes C were thzen categorized into Asian mtDNA type. Sequence analysis of the SRY gene on the Y‐chromosome in 67 male Kazakhstani goats revealed two haplotypes: Y1A (64%) and Y2A (36%). Analysis of the distribution of mtDNA haplogroups and SRY haplotypes from Eurasia and Africa demonstrated genetic similarity among animals from Kazakhstan, Mongolia, and Northwest China located on the Eurasian Steppe belt. These phylogeographic results suggested that the Eurasian Steppe belt was an important propagation route for goats to Central Asia.     

鸡传染性支气管炎病毒对新城疫病毒的干扰作用观察

为观察鸡传染性支气管炎病毒（IBV）HN99株对新城疫病毒（NDV）增殖的干扰作用,该试验采用不同浓度的IBV标准株M41和地方株HN99与鸡新城疫病毒（NDV）分别按不同接种顺序同胚增殖,利用病毒血凝试验（HA）测定NDV的效价,观察IBV对NDV的干扰作用,从而为检测IBV地方株HN99提供方法,也为同胚增殖两种病毒提供一系列的数据参考。试验结果表明,鸡传染性支气管炎病毒地方株HN99对NDV的干扰作用与其浓度和接种顺序有关。     

黄花梨茎段培养及植株再生

以黄花梨的顶芽和带芽茎段为外植体,研究了不同生长调节剂组合对其丛生芽诱导及生根的影响。结果表明:顶芽和带芽茎段以0.1%的HgCl2分别处理10、13min为宜;适宜的增殖培养基是MS+1mg/L 6-BA+0.5mg/L IAA;适宜的生根培养基是MS+2.0mg/L IBA+0.5mg/L NAA。     

茵陈的组织培养与快速繁殖

以茵陈的茎尖和茎段为外植体,研究了不同浓度6-BA和NAA外源激素配比组合对其离体培养的影响.结果表明:茎尖比茎段更适合做外植体;适宜的诱导培养基为MS+BA 0.1mg/L+NAA 0.1 mg/L;继代增殖培养基为MS+BA 0.1mg/L+NAA 0.1 mg/L;生根培养基为1/2MS+NAA 0.1 mg/L.     

细鳞裂腹鱼人工繁殖研究

2005～2006年,分别用4种不同的催产剂组合对经人工驯养的180余尾性成熟的野生细鳞裂腹鱼(Schizo-thoraxchongi)进行了人工催产,共获得受精卵50余万粒,孵化出仔鱼9万余尾。催产效果较好的催产剂组合为:鲤鱼脑垂体(PG)与人绒毛膜促性腺激素(HCG)联合二次注射,第一次注射剂量为(5 mg+600 IU)/kg鱼体重,第二次注射剂量为(12 mg+1000 IU)/kg鱼体重,在水温13～18℃效应时间为85～98 h。     

亳菊的组织培养快繁技术研究

[目的]探讨亳菊组织培养的快繁技术。[方法]以亳菊的茎尖作为外植体,以MS为基本培养基,附加不同剂量的NAA和6-BA,分别进行丛生芽诱导、增殖和生根培养,考察不同激素配比的培养基对亳菊丛生芽形成与生长的影响,以及对试管苗长势和生根的影响,并根据丛生芽的数量、长势、苗高、根条数、繁殖周期等指标,筛选适合亳菊茎尖离体组织培养的培养基配方。[结果]亳菊诱导分化的最佳培养基配方为MS＋6-BA0.50 mg/L＋NAA0.10 mg/L;增殖培养的最佳培养基配方为MS全量培养基;诱导生根的最佳配方为1/2MS＋IBA0.30 mg/L。将试管苗移栽到土∶泥炭∶珍珠岩为1∶1∶1的基质中,其成活率达99%,大田移栽的试管苗成活率可高达97.9%。[结论]该研究所筛选的培养基配方可作为亳菊脱毒培养的最优技术方案。     

藻百年的组培快繁技术研究

[目的]研究藻百年（Exacum tetragonum）的离体培养和快速繁殖技术。[方法]利用藻百年的茎尖和茎段作为外植体进行组织培养和快速繁殖。[结果]结果表明,MS＋6-BA2mg/L＋NAA0.2 mg/L＋蔗糖30 g/L＋琼脂8 g/L为最适诱导培养基;MS＋6-BA1 mg/L＋NAA0.1 mg/L＋蔗糖30 g/L＋琼脂8 g/L为最适增殖培养基,1/2 MS＋NAA0.3 mg/L＋蔗糖30 g/L＋琼脂8 g/L为最适生根培养基。[结论]该研究可为其他龙胆科植物的组织培养与快速繁殖提供方法参考。