普通菜豆(Phaseolus vulgaris L.)AOX基因家族鉴定与表达分析

交替氧化酶(Alternative oxidase,AOX)是一种末端氧化酶,在维持植物正常生长代谢速率和代谢平衡以及抵御逆境胁迫中发挥了一定作用。AOX家族成员已经在很多植物物种中被鉴定,但是在普通菜豆(Phaseolus vulgaris L.)中却未见报道。研究对普通菜豆中AOX家族成员进行了鉴定和分析,并进一步解析了AOX基因家族成员的功能及调控机制。结果表明,基于普通菜豆参考基因组中共挖掘得到了4个AOX家族成员,通过进化关系、保守基序(Motifs)、基因结构分析,将各成员划分成4个亚族。此外,顺式作用元件、共线性与盐胁迫下的表达量分析结果表明,AOX成员可能在植物的非生物胁迫响应中发挥了作用。为后续深入研究普通菜豆中AOX成员的功能奠定了理论基础。

Effect of Biostimulants Based on Natural Products on the Growth and Nutritional Value of Bean (Phaseolus vulgaris L.)

Beans (Phaseolus vulgaris L.) are widely grown in Cameroon and play a key role in the fight against food insecurity, malnutrition and poverty. However, its cultivation encounters problems due to abiotic and biotic stresses, which leads to the use of synthetic fertilizers and pesticides, which cause significant damage to the environment and human health due to the presence of synthetics residues in the seeds, pods and in the leaves that are eaten. Promoting the use of natural products is becoming a necessity for organic and eco-responsible agriculture that limits contamination problems and improves people’s purchasing power. This study aims to assess the effect of biostimulants based on natural products on the growth and nutritional value of common bean (Phaseolus vulgaris L.). Bean seedlings from white variety (MEX-142) and red variety (DOR-701) were treated every seven days in the field from their pre-emergence, emergence and growth to their maturation under a randomized block experimental design. Six treatments and three repetitions with the biostimulants based on natural products and controls were thus performed and the agromorphological parameters were measured. After 120 days, the contents of growth biomarkers and defense-related enzymes were evaluated in leaves, while the contents of macromolecules, minerals and antinutrients were evaluated in seeds. These biostimulants significantly increased (P P < 0.0001) of antinutrients including oxalates, phytates, tannins and saponins in seeds compared to controls (T+ and T−). Treatment with biostimulants, in particular BS4, improves the performance of bean plants in the field as well as the biofortification of seeds regardless of the variety.

Comparative Experiments on Different Varieties of Phaseolus vulgaris L. under Dry Farming Conditions

[Objective] The aim was to screen varieties of Phaseolus vulgaris L.for cultivation in arid,semi-arid areas.[Method] The cultivation experiments of seven varieties of P.vulgaris under dry farming conditions were carried out in typical dry farming agriculture region Yangqu County in North China.[Result] The plants of Teyoutejiadou,Chaojiwujing and Xinxinyichiqingyuanlong were relatively strong;the growth rate of Aifeng,Jingxuanjiadouwang and Chaochangsijidou was relatively rapid;the transpiration rate of functional leaves of Aifeng was the lowest.The yield of Tianma 95-33 jiadouwang was significant higher than that of other varieties,the unit yield was up to 36.33 t/hm2,which was 1.39 times higher than that of Aifeng and 1.9 times higher than that of Xinxinyichiqingyuanlong;followed by the yield of Aifeng（26.07 t/hm2）,which was 1.37 times higher than that of Xinxinyichiqingyuanlong.[Conclusion] The yield of Tianma 95-33 jiadouwang and Aifeng was relatively high,as well as the protein content,indicating that they were suitable to be applied and cultivated in the experimental plot and surrounding areas.

紫冠豆角(Phaseolus vulgaris L.)种子中α-淀粉酶抑制剂的提取及其性质研究

本研究采用盐溶的方法从紫冠豆角(Phaseolus vulgaris L.)种子中提取α-淀粉酶抑制剂(α-AI),将提取的α-AI用不同温度和pH处理,并评价其稳定性。在此基础上,以提取物对猪胰腺α-淀粉酶的抑制活性(IC_(50))为指标,分析了豆粉的细度(A)、料液比(B)、盐溶时间(C)三个因素对α-AI提取效果的影响,利用响应面分析法优化提取条件,通过对老豆角种子的深加工,实现提高其附加值的目的。结果表明:该α-AI为耐热性蛋白,在pH4~10的范围性质稳定,影响α-AI的IC_(50)因素按主次顺序排列为:豆粉的细度>料液比>盐溶时间,确定提取α-AI最佳工艺条件为:豆粉过60目筛(粒径<0.3 mm),料液质量体积比为1∶12(g/mL)、盐溶时间7.75 h。紫冠豆角种子α-AI的IC_(50)最优值为27.036±0.235μg/mL。

Leaf area development, dry weight accumulation and solar energy conversion efficiencies of Phaseolus vulgaris L. under different soil moisture levels near Nairobi, Kenya

Leaf area development, dry weight accumulation and solar energy conversion efficiencies of Phaseolus vulgaris L. cv GLP\|2 under two soil moisture levels in two contrasting seasons near Nairobi, Kenya were investigated. The experiment confirms that dry weights and yields of Phaseolus vulgaris are limited by a drought induced decrease in leaf area, leading to less radiation interception as a source for assimilation. However, photosynthetic efficiency in Phaseolus vulgaris also appears to decrease and to contribute to these effects. Finally, an even larger decreases of economic efficiency as obtained in the second season, where stress lasted much later into the season, reveals that such a drought also limits considerably the partitioning and translocation of assimilates to the seeds of Phaseolus vulgaris. The efficiencies obtained are in line with the better literature data for other crops.

Effects of Different Ridge Culture Ways on Stem Diameter,Plant Height,the Number of Leaves and Yield of Phaseolus vulgaris L. under Dry Farming Conditions

The variety "Aifeng" was used as experimental material,and the stem diameter,plant height,the number of leaves and yield of P. vulgaris under three ways of ridge culture (bedding,high ridge and M ridge) were observed and detected to study the effects of different ridge cultures on the growth and yield. The results showed that the stem diameter,plant height,the number of leaves and yield under M ridge culture were higher than that of bedding and high ridge.

Ultrastructural Analysis of the Ontogenetic Development of Shoot Induced from Embryonic Axes of Costa Rican Bean Varieties (<i>Phaseolus vulgaris</i>L.) under <i>in Vitro</i>Conditions by Scanning Electronic Microscopy

Common bean (Phaseolus vulgaris L.) is an economic important crop and one of the major grain legumes for human consumption in Latin America, Africa and Asia. A morphological study of shoot induced from embryonic axes development in four Costa Rican bean varieties (Brunca, Huetar, Guaymi and Bribri) cultivated on MS media with or without 5 mg·L–1 de N6-benzylaminopurine (BAP) by scanning electron microscopy (SEM) was developed in the present work. Micrographs showed similarities and differences in the ultrastructure of the apical dome, epidermal surface, stomata and different types of trichomes in the varieties cultivated on organogenesis media. Genotypes with advantageous morphological characteristics for genetic transformation, in particular an exposed apical dome, were identified. This work will contribute to the optimization of the in vitro regeneration of four common bean varieties.

Response of Eight Market Classes of Dry Bean (<i>Phaseolus vulgaris</i>L.) to Pendimethalin

There is little information on the tolerance of dry bean to pendimethalin. Field studies were conducted in 2007 to 2009 at Exeter, Ontario and in 2008 and 2009 at Ridgetown, Ontario to evaluate tolerance of black, cranberry, kidney, otebo, pink, pinto, Small Red Mexican and white bean to the pendimethalin applied preplant incorporated at 1080 and 2160 g.a.i.ha-1. Pendimethalin PPI caused minimal injury in most market classes of dry bean at 1 and 2 WAE. There was no injury in various market classes of dry bean with the low dose at 1 and 2 weeks after emergence (WAE). However, at the high dose there was 0 to 4% injury at 1 WAE and 0 to 7% injury at 2 WAE in black, cranberry, kidney, otebo, pink, pinto, SRM and white bean. Pendimethalin PPI was more injurious in white bean than in black, cranberry, kidney, otebo, pink, pinto and SRM bean. Pink and SRM bean exhibited the most tolerance to pendimethalin applied PPI at 1080 g.ai.ha-1 or 2160 g.ai.ha-1. Pendimethalin caused no adverse effect on plant height, shoot dry weight, seed moisture content and seed yield of black, cranberry, kidney, otebo, pink, pinto, SRM and white bean. Based on these results, there is an adequate margin of crop safety for pendimethalin applied PPI at the proposed dose of 1080 g.ai.ha-1 in black, cranberry, kidney, otebo, pink, pinto, SRM and white bean in Ontario.

Nutritional and Mineral Variability in 52 Accessions of Common Bean Varieties(Phaseolus vulgaris L.)from Madeira Island

The Phaseolus vulgaris L. is one of the traditional and most important leguminous crops in the Island of Madeira. The island’s bioclimatic tiers, agro-ecological environment and traditional farming practices had a great influence on the evolution of regional bean landraces. The variability of the nutritional and mineral seeds composition of 59 accessions of the Madeiran landraces, standard and commercial varieties was evaluated. Wide ranges of variability in biochemical parameters were reported among the Madeiran landraces, being the best sources of protein and mineral nutrition, according to the statistical results and literature comparative evaluation. Specifically, the content (g per 100 g DW) of ash ranged from 3.64-5.67, lipids from 0.57-2.86, protein from 18.55-29.69, starch from 23.40-52.65, soluble sugars from 2.97-6.84, while content of dry matter was from 83.35-93.55. The seeds also contained (per 100 g DW) between 2.55-4.83 g N, 0.30-7.50 g P, 1.30-2.49 g K, 0.10-0.18 g Mg, 4.10-10.00 mg Fe, 50.0-1.40 mg Cu, 2.20-5.00 mg Zn, 0.90-3.80 μg Mn and 0.20-2.40 μg B. This variability implies that the screened germplasm could serve as a source for breeding new varieties with improved biochemical and nutritional traits or could be highly recommended to meet specific dietary requirements. The cultivar Vaginha Grossa (ISOP 713) revealed low carbohydrate content that could be a good food choice for diabetics, while cultivar Vermelho (ISOP 724) bean should be offered as a valuable alternative source of protein and minerals in the local diet.

Photosynthetic Gas Exchange and Nitrogen Assimilation in Green Bean Plants Supplied with Two Sources of Silicon

Beans contain a wide range of vitamins,proteins,calcium,and zinc which make them an important food source for many countries.To meet the demand for bean production worldwide,large amounts of fertilizers and pesticides are used.However,the cost of production and environmental impact increases.To produce food sustainably,the use of beneficial nutrients such as silicon as a biostimulant has been proposed.However,information about the effect of different sources of silicon on the metabolism of bean plants is scarce.Bean plants cv.Strike were grown in pots for 60 days and the effect of foliar application of silicon nanoparticles and the silicon-based biostimulant Codasilat 4 concentrations(0,1,2,and 4 mM)on total biomass,yield,photosynthetic pigment concentration,photosynthetic activity,stomatal conductance,transpiration rate,chlorophyll fluorescence,and nitrogen assimilation were evaluated.The results obtained showed that the supply of silicon at a dose of 1 mM functioned as a biostimulant,favoring gas exchange and nitrogen assimilation within the plant,which stimulated growth and yield.The results of this research work allowed a better comprehension of the effects of silicon application through silicon nanoparticles and the biostimulant Codasilon the physiology of green bean plants.

六价铬对红芸豆种子萌发和幼苗生长的毒害作用及外源NO的缓解效应

为了研究铬(Cr)对红芸豆种子萌发和早期幼苗生长的胁迫作用及硝普钠(SNP,NO供体)的缓解作用,以红芸豆品种‘红芸3号’为试材,采用纸间发芽方法和水培法,研究Cr和外源NO对红芸豆种子萌发、种胚和幼苗抗氧化系统、幼苗光合特性以及营养元素吸收转运的影响。结果表明,20μmol·L^(−1)K_(2)Cr_(2)O_(7)胁迫诱发红芸豆种胚和幼苗氧化损伤,抑制幼苗对营养元素的吸收和转运,降低幼苗光合作用,进而抑制红芸豆种子萌发和早期幼苗的生长。添加100μmol·L^(−1)SNP(外源NO)可减轻Cr对种胚和幼苗的氧化胁迫伤害,降低Cr在幼苗中的积累,促进幼苗对营养元素的吸收和转运,增强幼苗光合作用。种子萌发生长72 h时,20μmol·L^(−1)K_(2)Cr_(2)O_(7)胁迫下添加SNP,种胚H_(2)O_(2)、O_(2)^(-)和MDA含量分别比Cr胁迫处理降低36.15%、30.96%和34.97%;Cr胁迫下,添加SNP幼苗生长10 d,根系H_(2)O_(2)、O_(2)^(-)和MDA含量分别比Cr胁迫处理降低55.25%、48.60%和33.54%,叶片H_(2)O_(2)、O_(2)^(-)和MDA含量分别比Cr胁迫处理降低27.71%、36.40%和53.85%,根系活力比Cr胁迫处理升高59.16%;幼苗根和叶中Cr含量比Cr胁迫处理降低69.14%和24.08%,幼苗根中Mg、Fe、Cu和Zn含量比Cr胁迫处理分别增加37.10%、17.96%、5.17%和13.60%,幼苗叶中Mg、Fe、Cu、Zn元素含量比Cr胁迫处理分别增加32.57%、29.49%、22.45%和36.07%;幼苗净光合速率和PSⅡ最大光合效率比Cr胁迫处理提高58.60%和11.27%。外源NO通过诱导种胚抗氧化酶活性提高,降低幼苗对Cr的吸收,促进幼苗对营养元素的吸收和转运,增强幼苗光合作用,缓解Cr对红芸豆种子萌发和早期幼苗生长的胁迫作用。

外源褪黑素对碱胁迫下菜豆幼苗的缓解效应

以菜豆耐碱品种“粉冠”及相对碱敏感品种“1-4-3-1-1”为试材,采用营养液水培法,设置对照(CK)、外源0.1μmol·L^(-1)褪黑素(MT)、60 mmol·L^(-1)NaHCO_(3)溶液碱胁迫(S)、碱胁迫下添加褪黑素(S+MT)4个处理,研究了外源褪黑素对碱胁迫下菜豆幼苗生长及耐碱性的影响,以期为盐碱地区提高菜豆的耐碱能力提供参考依据。结果表明:褪黑素能够降低碱胁迫对菜豆幼苗生物膜的伤害,增加生物量、超氧化物歧化酶(SOD)活性以及可溶性蛋白质含量,提高叶片的脯氨酸和可溶性糖含量及根系的过氧化物酶(POD)活性;2个菜豆品种对碱胁迫的生理响应不同,“粉冠”的耐碱能力更强,褪黑素能够有效缓解碱胁迫对菜豆幼苗的伤害,而且对相对碱敏感品种“1-4-3-1-1”的缓解效果更好。

硝普钠浸种对复合盐碱胁迫下红芸豆种子萌发和内源激素含量的影响

为探究硝普钠(SNP,NO供体)浸种对复合盐碱胁迫下红芸豆种子萌发和内源激素含量的影响,以芸选2号红芸豆种子为材料,采用响应面(RSA)和主成分分析法(PCA)优选硝普钠浸种提高复合盐碱胁迫下红芸豆种子萌发的条件;以最佳硝普钠浸种条件对种子进行浸种处理,研究复合盐碱胁迫下,外源NO对种胚保护酶系统以及种胚内源激素含量变化的影响。结果表明,50 mmol·L^(-1)复合盐碱溶液胁迫下,以发芽率、发芽势、发芽指数、活力指数、根长和种胚干重为目标,经RSA和PCA得到SNP浸种促进盐碱胁迫种子萌发生长的最佳浓度为0.3 mmol·L^(-1),浸种时间为12 h。50 mmol·L^(-1)盐碱胁迫下,用0.3 mmol·L^(-1) SNP对种子浸种处理后,种子的发芽率和发芽势分别较去离子水浸种处理提高38.17和10.83个百分点,发芽指数和活力指数分别较去离子水浸种处理提高19.56%和23.74%。与去离子水浸种处理相比,0.3 mmol·L^(-1) SNP浸种处理种胚萌发72 h的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性分别提高9.26%、59.79%和36.14%;过氧化氢(H_(2)O_(2))、超氧阴离子(O_(2)^(-))和丙二醛(MDA)含量分别降低45.45%、37.71%和25.51%。盐碱胁迫下,0.3 mmol·L^(-1) SNP浸种处理相较于去离子水浸种处理,种胚脱落酸(ABA)含量降低,赤霉素(GA_(3))含量和GA_(3)/ABA值提高。其中种子萌发48和96 h时,SNP浸种处理种胚ABA含量分别较去离子水浸种处理降低12.89%和29.99%,GA_(3)含量分别较去离子水浸种处理升高12.52%和85.79%,GA_(3)/ABA值分别较去离子水浸种处理高3.45和2.06。综上,外源NO可通过提高盐碱胁迫下红芸豆种胚抗氧化酶活性,降低ABA含量来提高GA_(3)含量,进而减轻盐碱氧化胁迫伤害,促进种子萌发。本研究结果为红芸豆抗盐碱高产栽培提供了理论依据。

交替呼吸途径对CuCl_2胁迫下菜豆叶片光系统Ⅱ的保护作用

以"农普"12号菜豆幼苗为材料,采用1 mmol·L^(-1)的水杨基氧肟酸(SHAM)抑制交替呼吸途径活性,探讨了在Cu Cl_2胁迫下交替呼吸途径对菜豆幼苗叶片光系统Ⅱ的保护作用。结果表明,随着Cu Cl_2胁迫浓度的增加,菜豆幼苗叶片潜在最大光化学效率F_v/F_m、光适应下叶片的最大光化学效率F_v'/F_m'、PSⅡ的实际光化学效率Y(Ⅱ)以及光化学猝灭系数q P、叶绿素含量均呈下降趋势,而非光学猝灭系数NPQ和交替呼吸途径的容量水平则呈上升趋势。较之在Cu Cl_2处理下的菜豆幼苗,用交替呼吸途径抑制剂预处理后的菜豆再置于Cu Cl_2的胁迫下,则会导致F_v/F_m、F_v'/F_m'、Y(Ⅱ)、q P以及叶绿素含量的进一步下降和NPQ的进一步上升。上述观察表明,在Cu Cl_2胁迫下交替呼吸途径可以缓解PSⅡ光化学效率的下降、维持PSⅡ反应中心的开放程度、减少天线色素的热耗散以及缓解叶绿素含量的降低,从而保护菜豆叶片光系统Ⅱ免受Cu Cl_2胁迫的伤害。

2,4-表油菜素内酯对盐碱胁迫下芸豆幼苗生长及生理特性的影响

【目的】探讨外源2,4-表油菜素内酯(2,4-EBR)缓解芸豆幼苗盐碱胁迫伤害的生理机制,为应用2,4-EBR缓解豆类植物盐碱胁迫提供依据。【方法】以盆栽‘芸选2号’幼苗为材料,研究在100 mmol/L盐碱胁迫下,喷施0.1 mg/L 2,4-EBR和4.0 mg/L油菜素内酯抑制剂芸苔素唑(BRZ)对幼苗生长、光合气体交换参数、抗氧化酶活性和渗透调节物质含量的影响。【结果】盐碱胁迫下芸豆叶片卷缩枯萎,株高、叶面积、主根长、光合色素含量、净光合速率(P_(n))、蒸腾速率(T_(r))、气孔导度(G_(s))均显著下降(P<0.05),脯氨酸(Pro)、可溶性糖(SS)含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性,相对电导率(REC)、丙二醛(MDA)含量和胞间CO_(2)浓度(C_(i))显著升高。喷施2,4-EBR处理能缓解盐碱胁迫造成的叶片枯萎和卷缩,植株生长状况逐渐转好,同时有效降低幼苗叶片REC、MDA和C_(i),显著提高株高、叶面积、主根长、Pro、SS、P_(n)、T_(r)、G_(s)及SOD、POD、CAT和APX活性,但外源2,4-EBR诱导的这些芸豆抗盐碱效应在加入BRZ后受到逆转。【结论】外源2,4-EBR处理能够提高芸豆叶片抗氧化系统酶活性和渗透调节物质含量,减轻盐碱胁迫造成的膜脂过氧化伤害及对光合作用的非气孔限制,促进幼苗生长,增强抗盐碱能力。

Foliar Application of Calcium and Molybdenum in Common Bean Plants: Yield and Seed Physiological Potential

The foliar application of micro- and macronutrients is often practiced by farmers to improve yield and seed physiological potential. For calcium and molybdenum, positive results have been observed, even in soils with high nutrient content. The purpose of this study was to assess the effects of foliar applications of calcium and molybdenum on yield and seed physiological potential in common bean plants. A randomized block design was implemented, with the treatments fixed in a factorial scheme: two molybdenum rates (with or without) and four calcium rates, with four replications. The calcium rates applied on the leaves were 0, 150, 300 and 600 g·ha-1 for the first year of the investigation (2005) and 0, 300, 600 and 900 g·ha-1 for the second year (2006). In both years, the molybdenum rates applied on the leaves were 0 g·ha-1 (without) and 75 g·ha-1 (with). The results showed that the foliar calcium application, with or without molybdenum, did not improve yield. Foliar application of calcium alone improved seed physiological potential in common bean plants when applied at the full bloom stage.

Can Improve Iron Biofortification Antioxidant Response,Yield and Nutritional Quality in Green Bean?

The aim of this study was to evaluate the effect of iron biofortification on antioxidant response, yield and nutritional qualityof green bean (Phaseolus vulgaris L.) under greenhouse conditions. Fe was applied using two forms (FeSO4 and Fe-EDDHA) at four doses of application (0, 25, 50 and 100 μm) added under a hydroponic system, and were tested over a period of 40 days. The Fe content was assessed in seeds, as well as the activity of antioxidant enzymes, production of H2O2, yield and nutritional quality. The results being obtained indicated that the accumulation of Fe in bean seeds enhanced with the application of Fe-EDDHA at the dose of 25 μm. This demonstrated that low Fe application dose was enough to increase Fe levels in seeds of common bean. In addition, Fe-EDDHA application form at 50 μmol was the best treatment to improve crop yield. Respect to antioxidant system, chelated form of Fe (Fe-EDDHA) was more effective in the activation of antioxidant enzymes (CAT, SOD and GSH-PX), and a lower content of H2O2 in green bean seeds. Finally, to raise the Fe concentration in bean under biofortification program was a promising strategy in cropping systems in order to increase the ingestion of iron and antioxidant capacity in the general population and provided the benefits that this element offered in human health.

Physiological Performance of Common Bean Seeds Treated with Bioactivator with and without Moisture Restriction

The commonbean (Phaseolus vulgaris L.) is an important agricultural crop due to its nutritional properties. Insecticides and fungicides employed to control pests and diseases in the common bean may cause as yet unknown effects on the plant’s morphology and metabolism. Bioactivators are complex organic substances, capable of exerting modification upon growth patterns, plant DNA transcription, gene expression, metabolic enzymes and mineral nutrition. Thiamethoxam insecticide has shown positive action on the enhancement of vigor expression, phytomass accretion and the promotion of deeper root systems. The aim of this work was to evaluate the effect of thiamethoxam on the physiological performance of common bean seeds. Seeds from cultivars Pérola and IAPAR Siriri were treated to thiamethoxam concentrations of 0, 100, 200, 300, 400 and 500 mL&middotkg-1 seed. Physiological quality was measured through tests for germination value, first count, cold test, accelerated aging and seedling shoot and root lengths, all undertaken in the presence and absence of moisture stress. Thiamethoxam stimulated the physiological performance of common bean seeds under moisture stress or in the absence of it, with levels varying according to cultivar and seed lot. The best physiological seed performance was obtained within the range of 200 mL&middotkg-1 seed to 400 mL&middotkg-1 seed.

Response of Four Market Classes of Dry Beans to Halosulfuron Applied Postemergence at Five Application Timings

Six field trials were conducted over a three-year period (2011, 2012, 2013) at the Huron Research Station, Exeter, Ontario and University of Guelph Ridgetown Campus, Ridgetown, Ontario to determine the effect of five postemergence (POST) application timings (1 - 2 trifoliate, 3 - 4 trifoliate, 5 - 6 trifoliate, 1st flower and 1st pod stage) of halosulfuron (35 and 70 g·ai·ha-1) on the tolerance of adzuki, black, white and kidney beans. All treatments including the non-treated control were maintained weed free during the growing season. Halosulfuron applied POST in black, white and kidney bean caused as much as 8%, 8%, 7%, 4% and 2% injury 1 WAA and 4%, 4%, 2%, 2% and 1% injury 2 WAA at 1 - 2 trifoliate, 3 - 4 trifoliate, 5 - 6 trifoliate, 1st flower and 1st pod stage application timings, respectively. The injury observed was transient with 1% or less injury 4 WAA and there was no adverse effect on the shoot dry weight, plant height, seed moisture content and yield of black, white and kidney bean. Injury was substantially higher in adzuki bean at all application timings. Halosulfuron applied POST caused as much as 66%, 47%, 50%, 39% and 36% injury 1 WAA;77%, 68%, 64%, 51% and 42% 2 WAA;and 69%, 51%, 47%, 40% and 29% 4 WAA at 1 - 2 trifoliate, 3 - 4 trifoliate, 5 - 6 trifoliate, 1st flower and 1st pod stage application timings, respectively. Halosulfuron POST decreased shoot dry weight as much as 69%, 57%, 43%, 41% and 34%;plant height as much as 17%, 15%, 14%, 13% and 10%;and seed yield as much as 47%, 46%, 45%, 56% and 55% at 1 - 2 trifoliate, 3 - 4 trifoliate, 5 - 6 trifoliate, 1st flower and 1st pod stages, respectively. Based on these results, there is an adequate margin of crop safety for halosulfuron POST in black, white and kidney beans. However, there is not an adequate margin of crop safety for halosulfuron POST in adzuki bean at the application timings evaluated.

Effects of Different Agroecosystems on Prevalence of Different Species of Pests and Coccinellid Predators

This study was aimed at determining the effects of mixed and single cropping agroecosystems on the prevalence of different species of insect pests and coccinellids. It involved six growing crops： maize Zea mays L., beans Phaseolus vulgaris L. and cowpeas Vignaunguiculata L. Walp in single and mixed stands and sampling throughout the phenology of the crops. Eight insect pest species were recorded on maize grown alone, while thirty seven insect species were endemic on cowpea mono cropped and were of six orders whereas twenty two insect pest species occurred on beans. The predator population was most abundant in the mixed stands of maize and beans （2.33 predators per 30 aphids） as compared to their occurrence in pure stands of cowpeas （0.85 predators per 30 aphids） as there were numerous aphids on beans at pre-flowering phase that supported a higher population level of coccinellids. Also, predator population was at the peak during the tussling stage of maize as they fed on the pollen grains while aphids on cowpeas co-existed mutualistically with black ants that protected them against predation. The genus Cheilomenes spp. was the most ubiquitous predator with a mean of 4.00 individuals per 30 aphids while Hippodamiavariegata was the least abundant predator species with a mean of 0.92 individuals per 30 aphids in all the agroecosystems as the Cheilomenes spp. had a faster discovery rate, range of perception, effective capture efficiency and a shorter handling time of a prey.