豇豆抗锈病性苗期鉴定技术研究

根据不同的接种方法、接种物浓度、保湿时间和温度对豇豆锈病苗期抗病性表现的影响,筛选出一套方便、可行的苗期抗病性鉴定技术：即在２０￣３０℃温度下,用每视野含３０个孢子（１０×６倍）的夏孢子悬浮液于１￣２处复叶的喷雾接种,保湿１８￣２４ｈ,接种后１０￣１４ｄ调查２１个供试品种的病指指数,结果表明品种间抗病性差异显著,其中,益农红仁特长豆角表现免疫,金山长豆和成都紫荚白露表现为高抗。     

红豇豆根缘细胞对铝胁迫的响应

以红豇豆(Vigna.ungniculata.ssp.sesquipedalis.cv.chuangfeng)为材料,采用悬空气培法,研究红豇豆根缘细胞产生的数目、活性及对铝胁迫的响应。结果表明,红豇豆的边缘细胞数目先随着根的伸长而迅速增加,到根长为10mm时达到最多,约为5300个;随后,边缘细胞数目稍有减少,且较为稳定。边缘细胞的存活率较高,都大于85%,随着红豇豆根长的伸长,边缘细胞的活性逐渐增高。根冠果胶甲基酯酶(PME)的活性随着根的伸长而减小,表明边缘细胞游离与根冠PME活性有着密切的相关性。离体边缘细胞的存活率随着Al3+处理浓度和处理时间的增加而降低。不同浓度Al3+液处理对相同根长红豇豆的根冠PME酶活性没有显著的影响。     

丙二酸处理对豇豆采后贮藏品质的影响

以新鲜豇豆为试材,研究100、200、300、400 mg·L^-1 丙二酸处理的豇豆在(8±2) ℃贮藏期间锈斑指数及生理生化指标的变化。结果表明,贮藏12 d后,丙二酸处理的豇豆锈斑指数均显著低于对照,200、300 mg·L^-1 丙二酸处理效果最好;丙二酸处理的失重率始终低于对照,300 mg·L^-1 丙二酸处理显著低于对照;贮藏9 d时,丙二酸处理的豆荚、豆粒可溶性蛋白含量始终高于对照,贮藏12 d时,300 mg·L^-1丙二酸处理的豆荚可溶性蛋白含量最高,高于对照68.49%,豆粒可溶性蛋白含量高于对照6.42%;贮藏期间豇豆的叶绿素、维生素C含量呈下降趋势,300 mg·L^-1丙二酸处理组始终高于对照;豇豆豆荚、豆粒的可溶性糖含量在贮藏期间迅速下降,200、300 mg·L^-1丙二酸处理豆荚可溶性糖含量始终高于对照;豇豆的纤维素含量呈上升趋势,300 mg·L^-1丙二酸处理豇豆纤维素含量均显著低于对照组;豇豆多酚氧化酶(PPO)活性总体呈上升趋势,但在贮藏期间,丙二酸处理的PPO活性始终低于对照;所有处理的过氧化物酶活性均在第6天达到峰值然后下降,300、400 mg·L^-1丙二酸处理在贮藏期间过氧化物酶(POD)活性变化一直比较平稳。不同浓度丙二酸处理通过抑制豇豆锈斑指数增加,延缓失重率、纤维素含量、PPO活性的升高和叶绿素、可溶性糖、可溶性蛋白含量的降低,保持较高水平的POD活性清除自由基,来维持豇豆采后品质,从而提高豇豆采后保鲜效果;综合比较4个丙二酸浓度处理,以300 mg·L^-1 丙二酸处理豇豆保鲜效果最好。     

豇豆新品种丰豇绿优和丰豇一点红的选育

对丰豇绿优和丰豇一点红的选育过程、主要特性、产量表现等方面进行了介绍,并总结了栽培管理的技术要点。     

Water use efficiency and uptake patterns in a runoff agroforestry system in an arid environment

Water is the most limiting factor for plant production in arid to semiarid regions. In order to overcome this limitation surface runoff water can be used to supplement seasonal rainfall. During 1996 we conducted a runoff irrigated agroforestry field trial in the Turkana district of Northern Kenya. The effects of two different Acacia saligna (Labill.) H. Wendl. tree planting densities (2500 and 833 trees per ha), tree pruning (no pruning vs. pruning) and annual intercrops (no intercrop vs. intercrop: Sorghum bicolor (L.) Moench during the first season and Vigna unguiculata (L.) Walp. during the second season) on water use were investigated. The annual crops were also grown as monocrops. Water consumption ranged from 585 to 840 mm during the first season (only treatments including trees). During the second season, which was shorter and the plants relied solely on stored water in the soil profile, water consumption was less than half of that during the first season. Highest water consumptions were found for non-pruned trees at high density and the lowest were found for the annual crops grown as monocrops. Tree pruning decreased water uptake compared to non-pruned trees but soil moisture depletion pattern showed complementarity in water uptake between pruned trees and annual intercrops. The highest values of water use efficiency for an individual treatment were achieved when the pruned trees at high density were intercropped with sorghum (1.59 kg m^–3) and cowpea (1.21 kg m^–3). Intercropping and high tree density increased water use efficiency in our runoff agroforestry trial. We ascribe the observed improvement in water use efficiency to the reduction of unproductive water loss from the bare soil.This revised version was published online in November 2005 with corrections to the Cover Date.     

中国南方种植‘丰成黑籽1号’的高效栽培模式

北海地区主栽新品种‘丰成黑籽1号’在肉质、口感、抗病等方面具有多优秀的品质。从北海特殊气候方面考虑,围绕‘丰成黑籽1号’,结合病虫害防治和适时采收时节,探讨其高产高效栽培技术的要点。     

朱砂叶螨危害对豇豆幼苗叶绿素和蛋白质含量的影响

豇豆幼苗叶片受朱砂叶螨危害0～8 d内,叶绿素、蛋白质含量及组成随危害程度的加深均有不同程度的变化。在试验期内,受害叶片蛋白质含量随危害时间的延长稳定增加,与危害时间之间差异显著(P<0.05),在危害8 d时,两虫口密度之间也产生显著差异(P<0.05);在危害4 d后,受害叶片产生带8、9两条蛋白质谱带,且含量随危害时间的延长而增加;在实验期内,两处理叶片叶绿素a、叶绿素b及叶绿素总量均随危害时间的延长而下降,不同危害时间之间下降的幅度差异显著(P<0.05),另外,相同危害时间下两处理叶片叶绿素a、叶绿素b及叶绿素总量下降的幅度也随虫口密度的增大而增加,两虫口密度之间差异显著(P<0.05)。     

豇豆根瘤亚细胞组分中ASAL的分段盐析

68．5％的腺苷酸琥珀酸裂解酶(ASAL)活性和62．2％的5-氨基-4-咪唑-N-腺苷酸羧基酰胺核糖核苷酸(SAICAR)裂解酶活性分布在豇豆根瘤亚细胞的可溶性组分中。亚细胞可溶性和颗粒组分的ASAL和SAICAR裂解酶活性回收率均在50％-55％(NH4)2SO4饱和度分段盐析沉淀中出现1个峰值。但在颗粒组分提取液的60％-65％(NH4)2SO4饱和度分段盐析沉淀中,分别另有一个小的ASAL和SAICAR裂解酶活性回收率峰值出现。讨论了ASAL是1个双功能酶及其同工酶存在的可能性。     

豇豆种子耐贮性的三种人工老化方法的比较研究

 ２个豇豆品种经 ４０℃ 、１００／ＲＨ老化处理后，种子的发芽势、发芽率、发芽指数和活力指数等的变化趋势均与自然老化种子的死亡规律相似，呈近似反Ｓ型曲线；两用５８±１℃ 热水和５０％甲醇溶液老化处理去、２个品种的表现与自然老化种子的不同。因此．４０℃、１００％ＲＨ高温高湿适用于评价豇豆种子耐贮性的人工老化，其最适老化时间为５～６ｄ；适宜的生理生化指标为电导率。     

Does apoplastic ascorbic acid enhance manganese tolerance of Vigna unguiculata and Phaseolus vulgaris?

In cowpea (Vigna unguiculata), the development of manganese (Mn) toxicity is considered to be accompanied by the formation of reactive oxygen species, oxidized Mn, and phenoxy radicals in the leaf apoplast. Ascorbic acid (AA) is a common antioxidant in plants, and the oxidation of AA, particularly in the leaf apoplast, contributes to the first line of defence against several biotic and abiotic stress factors. The objective of the present study was to contribute to a better understanding of the role of AA in Mn leaf‐tissue tolerance of cowpea and common bean (Phaseolus vulgaris). Five cowpea cultivars (cvs.) differed greatly in Mn tolerance, which was expressed in differences in numbers of brown spots on leaves and in peroxidase (POD) activity in the apoplastic washing fluid (AWF). In a Mn‐sensitive cv., after 3 d of Mn treatment, brown spots were formed, and POD activities were increased, accompanied by a release of proteins into the apoplast. In the AWF, the concentration of AA and the ratio of AA : (AA+DHA) decreased already after 1 d, and to only 2% after 3 d. In the leaf tissue, the ratio was nearly unaffected, and the total AA+DHA content in the leaf tissue was even increased with advanced expression of Mn toxicity. The application of AA solutions in the range of 5–10 μM via the petiole slightly enhanced Mn tolerance as indicated by the reduction of brown spots (however inconsistently) and POD activity (consistently) in the AWF. Common bean cultivars differing in ozone tolerance, which has been reported to be due to a high AA availability in the leaf apoplast, were studied for their Mn tolerance. Clear differences in Mn tolerance between the cultivars existed, however, these differences were not related to their ozone tolerance. From these results, we conclude that the maintenance of sufficient AA levels in the leaf apoplast contribute to Mn tolerance, but does not fully explain genotypic differences in Mn tolerance in cowpea and common bean.