The role of glucosinolates and their hydrolysis products in oviposition and host-plant finding by cabbage webworm, Hellula undalis

The cabbage webworm, Hellula undalis (Fabricius) (Lepidoptera: Pyralidae), a tropical pest on crucifers (Brassicaceae), differentiated among host‐plant species for oviposition in laboratory and field tests. White mustard, Sinapis alba (L.) var. Selinda, was the preferred host‐plant, followed by Brassica juncea (L.) Czern. et. Coss var. Canadian brown mustard, and pak‐choi, Brassica campestris L. ssp. chinensis var. Joi Choi, Black Behi and Bai Tsai. Glucosinolates (GS), secondary plant compounds characteristic to the Cruciferae plant family, and their breakdown products were analyzed by using HPLC and GC‐MS‐techniques. Species differed in GS composition and concentration. Content of GS was highest in S. alba with progressively lower contents detected in B. juncea and B. chinensis. The aromatic GS, 4‐hydroxybenzyl‐GS and benzyl‐GS, were detected in S. alba. In B. juncea the alkenyl GS, allyl‐GS, dominated, whereas in varieties of B. chinensis indolyl and alkenyl GS predominated. Oviposition of H. undalis females on the non‐host‐plant Vigna unguiculata ssp. sesquipedalis (L.) Fruwirth was stimulated by application of GS extracts from the crucifer species; the extract from S. alba was preferred, followed by extracts from B. juncea and B. chinensis. Hydrolysis of GS in the plant extract from B. chinensis causes loss of the oviposition stimulatory effect of the extract. Application of the GS, allyl‐GS, and benzyl‐GS also stimulated oviposition by H. undalis. Significantly more eggs were laid on leaves treated with the aromatic GS, benzyl‐GS, than with the alkenyl GS, allyl‐GS. Host‐plant odor attracted H. undalis females but not males, in behavioral assays conducted in a Y‐tube olfactometer. Low concentrations of the GS hydrolysis product, allyl‐isothiocyanate, induced anemotaxis of females, but a high concentration of allyl‐isothiocyanate was repellent. Oviposition by H. undalis females was not stimulated by host‐plant volatiles. Females laid eggs on inserted traps and the walls of the Y‐tube regardless of presence or absence of host‐plant odor. The relevance of these results in the context of crucifer‐insect interactions is discussed.     

Characteristics of oviposition behaviour of the pollen beetle, Meligethes aeneus on four different host plants

Oviposition behaviour of Meligethes aeneus F. (Coleoptera: Nitidulidae) is characterised and quantified on four different plant species. Six behavioural components are identified: W—walking, WA—walking with abdomen on surface, R—resting, B—biting, AOH—placing abdomen over the bite hole and OVI—oviposition. Comparison of host acceptance behaviours on Brassica napus L., Brassica juncea (L.) Czern, Brassica nigra (L.) Koch and Sinapis alba L. showed that S. alba was accepted as a host only after a long exposure to the plant. Behaviour on the Brassica species was similar, however on B. nigra beetles spent a high proportion of time actually ovipositing. We conclude that important cues for oviposition are located both on the bud surface and inside the bud.     

Glucosinolate profile and oviposition behavior in relation to the susceptibilities of Brassicaceae to the cabbage seedpod weevil

Understanding how host‐plant characteristics affect behavioral and physiological responses of insect herbivores is of considerable importance in the development of resistant crop germplasm. Feeding, oviposition preference, larval development, and oviposition behavior of the cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham) (= Ceutorhynchus assimilis Payk.) (Coleoptera: Curculionidae), were investigated on eight Brassicaceae species that differed in their glucosinolate profiles. The least preferred host plants for feeding and oviposition were the Sinapis alba L. lines while the Brassica carinata L. line was most preferred. Larval development occurred most rapidly on Brassica rapa L. and slowest on S. alba. Larval weight was highest on B. napus L. and lowest on S. alba. Total glucosinolate levels did not influence C. obstrictus larval growth or development; however high levels of specific glucosinolates such as p‐hydroxybenzyl and 3‐butenyl glucosinolate were associated with increased developmental time or reduced weight. The time required for oviposition behavioral events was measured on different host‐plant species: B. rapa, B. napus, B. napus×S. alba, B. tournefortii Gouan., B. juncea (L.) Czern, B. carinata, B. nigra (L.) Koch., and S. alba. The early steps in the sequence were completed faster on more susceptible host plants (B. carinata, B. napus, and B. rapa) than on relatively resistant ones (B. tournefortii and B. juncea). Females explored pods of B. nigra and S. alba, but oviposition occurred only rarely on these species. There was no significant difference in the location on the pod on which oviposition occurred among the different plant species. Mean eggs laid per female weevil were highest on the B. napus×S. alba hybrid and lowest on B. nigra and S. alba.     

火炭母的一个新异名及其系统位置初探

该文将铺地火炭母(Polygonum chinense L. var. procumbens Z. E. Zhao et J. R. Zhao)处理为火炭母原变种(Persicaria chinensis var. chinensis)的异名,并讨论了火炭母在命名上的问题,及其系统学位置。     

Alternaria incidence in some alloplasmic lines of Indian mustard (Brassica juncea (L.) Coss.)

Summary The cytoplasmic substitution lines of Brassica juncea (L.) Coss were evaluated for their field resistance to Alternaria blight (Alternaria brassicae). The euplasmic B. juncea cv. RLM 198 had a mesothetic reaction while alloplasmic B. juncea lines with cytoplasms of B. campestris, B. chinensis, and B. japonica were highly susceptible. B. nigra cytoplasm did not have any effect on the disease reaction of the B. juncea genome. However, the alloplasmic lines with the cytoplasm of B. napus and B. carinata revealed a comparatively higher degree of resistance. The study underlined the utility of cytoplasmic manipulations in modifying the phenotypic expression of nuclear genes.     

核桃青皮分解对小白菜生长及生理特性的影响

采用盆栽试验,研究了不同剂量核桃(Juglans regia L.)青皮在土壤中分解过程中对受体植物小白菜(Brassica rapa L.var.chinensis)幼苗生长及其生理特性的影响,探讨核桃青皮的化感作用机理。结果表明:(1)核桃青皮在施入土壤的75d内,显著抑制了小白菜地上部分生物量的积累。(2)各剂量青皮处理小白菜叶片的叶绿素含量在施入20d时均较CK降低,且随着处理时间延长总体呈减少趋势。(3)各剂量青皮处理小白菜叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)活性在施入20d和75d时大多比对照显著升高,且有随剂量增加而增强的趋势,但过氧化氢酶(CAT)活性则随添加量增大或处理时间延长多无显著变化。(4)小白菜叶片可溶性糖(SS)含量在施入20d时随青皮添加量的增加而增加,后期则表现为显著下降,而可溶性蛋白(SP)和脯氨酸(Pro)含量在整个处理期则呈减少趋势。研究认为,核桃青皮在土壤中分解可能对小白菜的生长和抗性生理指标产生了明显的化感作用,其化感作用强度随其分解时间延长呈先强后弱的变化趋势,且高添加量产生的效应比低添加量快而且强。     

Physical and chemical factors influencing landing and oviposition by the cabbage root fly on host-plant models

Various plant models were used in both choice and no-choice tests in the laboratory to assess landing and oviposition preferences of the cabbage root fly,Delia radicum (L.). The main factor governing the site most suitable for landing was the conspicuousness of the object and not its shape. Oviposition was influenced considerably by the pre-conditioning of the females. Deprived females laid eggs even when denied access to both host plant chemicals and host-plant models. The dominant role of contact chemical stimuli in host acceptance was reconfirmed, but only a combination of physical and chemical stimuli appeared capable of eliciting normal oviposition. The combination of contact chemical stimuli and the presence of a stem on the test model had a synergistic effect on the numbers of eggs laid in both choice and no-choice situations. In choice bioassays, female cabbage root flies distinguished between models of different shapes, heights and sizes. The size and shape of the models appeared to be perceived in part after the flies had landed.     

Oviposition behaviour of Dasineura brassicae on a high- versus a low-quality Brassica host

The oviposition behaviour of the brassica pod midge, Dasineura brassicae Winn. (Diptera: Cecidomyiidae), on a preferred host, Brassica napus L. (summer oilseed rape) was compared to that on a nonpreferred, less suitable host for larval growth, Brassica juncea (L.) Coss & Czern (brown mustard). The experiments were done under field conditions with wild females.The number of landing females was significantly higher on B. napus than on B. juncea, indicating host differences in olfactory and/or visual stimuli. After landing, the behaviour differed in that females stayed longer and laid more egg batches on B. napus than on B. juncea plants. The probability that oviposition would occur after landing and the potentially adjustable egg batch size were similar on the high- and the low-quality host.A larger egg load on B. napus than on B. juncea can thus be attributed mainly to a higher landing rate and more repeated ovipositions occurring on B. napus.

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Comportement de ponte de Dasineura brassicae sur des Brassica de qualites élevée et basse

Résumé La comparaison porte sur le comportement de ponte de D. brassicae Winn. (Dept. Cecidomyiidae) sur Brassica napus L., hôte préféré, et sur B. juncea L., hôte non-préféré, qui convient moins au développement larvaire. Les expériences réalisées en champ ont porté sur des femelles sauvages.Le nombre de femelles qui atterrissent sur B. napus est significativement plus élevé que sur B. juncea, ce qui indique des différences entre les stimuli olfactif et visuel des plantes-hôtes. Aprés atterrisage, le comportement diffère en ce que les femelles restent plus longtemps et déposent plus de pontes sur B. napus que sur B. juncea. La probabilité pour que la ponte suive l'atterrissage et les tailles des ooplaques potentiellement ajustables sont semblables sur les hôtes de qualité élevée ou basse.Une charge supérieure en oeufs sur B. napus que sur B. juncea peut ainsi être principalement attribuée à un taux d'atterrissage plus élevé et à une plus grande fréquence de ponte sur B. napus.

     

Male sterility caused by cytoplasm of Brassica oxyrrhina in B. campestris and B. juncea

Summary Synthetic alloploid Brassica oxyrrhina (2n = 18, OO) x B. campestris (2n = 20, AA) was repeatedly backcrossed with B. campestris to place B. campestris nucleus in the cytoplasm of B. oxyrrhina. Alloplasmic plants, obtained in BC₅ generation, were stably male sterile but mildly chlorotic during initial development. Synthetic alloploid B. oxyrrhina-campestris was also hybridized with B. juncea to transfer B. oxyrrhina cytoplasm. Segregation for green and chlorotic plants was observed in BC₁ and BC₂ generations. By selection, however, normal green male sterile B. juncea was obtained in BC₃. Pollen abortion in both B. campestris and B. juncea is post-meiotic.     

Pollen beetle (Meligethes aeneus) oviposition and feeding preference on different host plant species

The oviposition and feeding preferences of the pollen beetle, Meligethes aeneus, were determined in choice and no-choice tests in field, semi-field and greenhouse trials. Plant species used were Brassica napus, B. campestris, B. juncea, B. nigra, B. carinata, Sinapis alba and Crambe abyssinica. With respect to number of eggs laid, S. alba and C. abyssinica were inferior to the other species. Pollen beetles laid fewer eggs on B. nigra than on the other Brassica spp. in no-choice tests, however this difference was partly due to fewer eggs laid per bud rather than fewer buds used for oviposition. Most eggs, for all plant species, were deposited in buds sized 2–3 mm. Feeding damage on all plant species was relatively similar. Pollen beetles seem to have a wider host range for feeding than for oviposition. There was good agreement in plant species ranking as oviposition hosts between the field, semi-field and greenhouse trials.     

Oviposition and larval performance of Rabdophaga terminalis on Salix spp. with special consideration to bud size of host plants

Females of the gall midge Rabdophaga terminalis (H. Loew) (Diptera: Cecidomyiidae) are very selective in their choice of host plants at oviposition. In preference trials, eggs were laid almost exclusively on S. alba and S. fragilis. One single oviposition occurred on S. viminalis but none on S. triandra, S. daphnoides or S. smithiana. Significantly more eggs were laid on S. alba than on S. fragilis. No differences were detected between clones of the same species regarding oviposition in laboratory trials. Within the species of S. alba, larger buds were preferred. However, this did not explain the preference of S. alba to S. fragilis. There was agreement between plant species selected by the females and survival of the larvae. No galls developed when eggs were transferred to species that were not oviposited on. There was no difference between S. alba and S. fragilis in larval growth, but after two weeks of development there was a significantly higher proportion of larvae in cocoons and pupae on S. alba. There was a negative linear relationship between weight of larvae and larval number per gall, indicating larval competition. The negative slope was steeper for S. alba than for S. fragilis when larvae were weighed after two weeks of development. There were some discrepancies between laboratory and field data on infestation of S. alba and S. fragilis. Higher infestation levels were related to denser stands in the field.

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Résumé Etude de la ponte et des performances larvaires de Rabdophaga terminalis (Diptera; Cecidomyiidae) sur plusieurs espèces de saules avec examen particulier de l'influence de la taille des bourgeons.La ponte et les performances larvaires de la cécidomyie galliforme, Rabdophaga terminalis (H. Loew) ont été étudiées sur plusieurs espèces et clones de saules cultivés en Suède. Les femelles sélectionnent avec soin les plantes hôtes lors de la ponte. Dans des essais préférentiels, les oeufs ont été pondus presque exclusivement sur S. alba et S. fragilis; une ponte a été observée sur S. viminalis et aucune sur S. triandra, S. daphnoïdes ou S. smithiana. Significativement plus d'oeufs ont été pondus sur S. alba que sur S. fragilis. Les essais au laboratoire n'ont pas permis de déceler des différences entre clones de la même espèce. Chez S. alba, les plus gros bourgeons étaient préférés, mais ceci ne permet pas d'expliquer la préférence pour S. alba par rapport à S. fragilis. Il y a coïncidence entre les plantes choisies par les femelles et al survie des larves; il n'y avait pas développement de galles quand des oeufs étaient transférés sur des espèces qui n'avaient pas reçu de pontes. La croissance larvaire sur S. alba et S. fragilis ne présentait pas de différences, mais après 2 semaines de développement il y avait significativement plus de larves en cocons et pupes sur S. alba. La corrélation entre le poids des larves et le nombre de larves par cellule était linéaire et négative, ce qui indique une compétition larvaire; la pente était plus raide pour S. alba que pour S. fragilis quand les larves étaient pesées au bout de 2 semaines de développement. Il y a eu quelques discordances entre les résultats au laboratoire et les données de terrain sur la contamination de S. alba et S. fragilis. Les plus fortes contaminations étaient observées à l'extérieur sur pépinières denses.

     

Intergeneric hybridization between Diplotaxis siifolia,a wild species and crop brassicas

Summary Attempts were made to obtain intergeneric hybrids between Diplotaxis siifolia, a wild species, and cultivars of Brassica (B. campestris, B. juncea, and B. napus). The crosses showed unilateral incompatibility. When the wild species was used as female parent, pollen germination and pollen tube growth were normal, but hybrid seeds aborted due to post-fertilization barriers. Reciprocal crosses (cultivars as female parent) showed strong pre-fertilization barriers; although pollen grains showed germination, pollen tubes failed to enter the stigma. Hybrids were realized in two of the crosses, D. siifolia x B. juncea and D. siifolia x B. napus, through ovary culture. The hybrids were multiplied in vitro by multiplication of axillary shoots, or somatic embryogenesis. Detailed studies were carried out on the hybrid D. siifolia x B. juncea. F₁ hybrids had shrivelled anthers and were pollen sterile. Amphiploids of this hybrid showed 60% pollen fertility and produced seeds upon self-pollination as well as backcross pollination with the pollen of B. juncea.     

Oviposition habitat selection in response to risk of predation in temporary pools: mode of detection and consistency across experimental venue

Natural selection should favor females that avoid ovipositing where risk of predation is high for their progeny. Despite the large consequences of such oviposition behavior for individual fitness, population dynamics, and community structure, relatively few studies have tested for this behavior. Moreover, these studies have rarely assessed the mode of detection of predators, compared responses in prey species that vary in vulnerability to predators, or tested for the behavior in natural habitats. In an outdoor artificial pool experiment, we tested the oviposition responses of two dipteran species, Culiseta longiareolata (mosquito) and Chironomus riparius (midge), to the hemipteran predator, Notonecta maculata. Both dipteran species have similar life history characteristics, but Culiseta longiareolata larvae are highly vulnerable to predation by Notonecta, while Chironomus riparius larvae are not. As their vulnerabilities would suggest, Culiseta longiareolata, but not Chironomus riparius, strongly avoided ovipositing in pools containing Notonecta. An experiment in natural rock pools assessing oviposition by Culiseta longiareolata in response to Notonecta maculata yielded an oviposition pattern highly consistent with that of the artificial pool experiment. We also demonstrated that the cue for oviposition avoidance by Culiseta longiareolata was a predator-released chemical: Notonecta water (without Notonecta replenishment) repelled oviposition for 8 days. Oviposition avoidance and mode of detection of the predator have important implications for how to assess the true impact of predators and for the use of commercially produced kairomones for mosquito control.     

Ammonia assimilation and metabolism byBeggiatoa alba

Beggiatoa alba B18LD was investigated for its pathways of ammonia assimilation. The increase in growth yields ofB. alba with excess acetate was linear from 0.1 to 2.0 mM ammonia.B. alba had strong glutamine synthetase (GS) and glutamate synthase (GOGAT) activities, irrespective of the ammonia concentration in the medium. Glutamate dehydrogenase activity was not found, and alanine dehydrogenase (aminating) was observed only whenB. alba was grown at high (2.0 mM) ammonia. Methionine sulfoximine, an inhibitor of GS, inhibited growth ofB. alba irrespective of the ammonia concentration in the medium. Thus it appears the primary pathway for ammonia assimilation inB. alba is via the GS-GOGAT pathway at both low and high ammonia concentrations. Preliminary experiments were unable to discern if theB. alba GS is modified by covalent modification.Non-standard abbreviations GS Glutamine synthetase - GOGAT glutamate-oxoglutarate aminotransferase - GDH glutamate dehydrogenase - ADH alanine dehydrogenase - MSX methionine sulfoximine - GOT glutamate-oxaloacetate aminotransferase - GPT glutamate-pyruvate aminotransferase     

药用植物华重楼(黑药花科)叶绿体全基因组研究

为探究华重楼(Paris polyphylla var. chinensis)的叶绿体基因组特征,利用叶绿体系统发育基因组学方法,对华重楼与其它百合目植物的叶绿体全基因组进行了比较。结果表明,华重楼的叶绿体全基因组长158307 bp,由4个区组成,包括2个反向重复区(IRA和IRB,27473 bp)、1个小单拷贝区(SSC,18175 bp)和1个大单拷贝区(LSC,85187 bp)。其叶绿体基因组有115个基因,包括81个编码蛋白质基因、30个转运RNA基因和4 个核糖体RNA基因。11种百合目植物的叶绿体全基因组的基因组成和基因顺序相似。华重楼的cemA基因是假基因,其起始密码子后有多聚核苷酸poly(A)及CA双核苷酸重复序列,编码序列中出现多个终止密码子, 且与北重楼(Paris verticillata)的cemA编码序列中的终止密码子位置不同。因此,华重楼叶绿体基因组比较保守;cemA结构及假基因化现象可能具有重要的进化与系统发育信息,其编码序列中的终止密码子可以区分华重楼和北重楼。     

Virulence of Agrobacterium tumefaciens strains with Brassica napus and Brassica juncea

Summary Brassica napus and Brassica juncea were infected with a number of Agrobacterium tumefaciens strains. Tumourigenesis was very rapid and extremely efficient on B. juncea with all but one of the strains. Tumourigenesis on B. napus varied widely. It was very efficient with the nopaline strains, was reduced with the succinamopine strain A281 and was very weak with the octopine strains. The latter observation was confirmed with six different B. napus rapeseed cultivars. The selectivity was due to differences in the virulence of Ti plasmids with B. napus, rather than the tumourigenicity of the T-DNA or virulence of the chromosomal genes associated with the strains. An exception was strain LBA4404. The virulence of the octopine strains was increased by coinfection with more virulent disarmed strains and by induction with acetosyringone.     

南方红豆杉水浸提液对喜树种子发芽和幼苗生长的化感作用

化感作用是影响人工混交林种间关系的重要因素之一。已有研究表明：喜树南方红豆杉混交对喜树生长有明显促进作用,并从混交改善混交林地微气候角度解释了这种促进作用,但未从种间化感作用角度探讨这种作用。为了探究南方红豆杉是否对喜树具有潜在的化感促进作用,从而更全面了解喜树南方红豆杉混交林种间关系,考察了不同浓度（25、50 g/L和100 g/L）的南方红豆杉（Taxus chinensis var.mairei）鲜叶、凋落叶、枝和根水浸提液对喜树（Camptotheca acuminata）种子发芽和幼苗生长的影响。结果表明：（1）南方红豆杉凋落叶浸提液对喜树种子发芽和幼苗生长无显著影响（P>0.05）,而鲜叶、枝和根浸提液对喜树发芽和幼苗生长均具有不同程度的促进作用（P<0.05）,且作用强度大体与浓度呈正相关;（2）100 g/L的南方红豆杉鲜叶、枝和根浸提液浸泡的喜树种子,其发芽率比对照组分别提高8.1%、14.9%和25.6%;（3）南方红豆杉鲜叶浸提液只有在高浓度（100 g/L）时,对喜树幼苗基径生长具有促进作用（P<0.05）,而对其株高、全株干重和净光合速率无显著影响;南方红豆杉根和枝浸提液对喜树幼苗株高、基茎、干重和净光合速率均具有促进作用（P<0.05）,与对照组相比,100 g/L的根和枝浸提液浇灌喜树幼苗,可以使喜树幼苗株高分别提高14.2%和8.4%,基径分别提高19.0%和15.3%,干重分别提高23.1%和15.9%,净光合速率分别提高11.6%和6.1%。研究结果表明,在喜树南方红豆杉混交林中,南方红豆杉对喜树的正向化感作用可能是促进喜树生长的重要因素之一。     

溶磷细菌和丛枝菌根真菌接种对南方红豆杉生长及根际微生物和土壤酶活性的影响

以南方红豆杉实生苗为材料,采用盆栽实验探讨了高效溶磷细菌草木樨中华根瘤菌(Sinorhizobium meliloti)CHW10B与丛枝菌根真菌缩球囊霉(Glomus constrictum)单独和双接种条件下,其植株生长、根际土壤可培养微生物数量、土壤酶活和土壤微生物功能多样性变化,在微生态水平揭示接种对南方红豆杉生长的影响及其机制。结果表明:(1)各接种处理对南方红豆杉幼苗均有促生长作用,接种处理苗高、地径和生物量均较对照显著增加,并以双接种促进效果最好。(2)各接种处理提高了南方红豆杉根际土壤可培养细菌、真菌和放线菌含量,增加了土壤微生物碳源利用率,改变了土壤中物种的丰富度和均一度,增加了土壤中的生物多样性。(3)各接种处理促进了南方红豆杉根际重要土壤酶(酸性磷酸酶、脱氢酶、转化酶)活力的增加,且双接种的促进作用最为明显。可见,溶磷细菌(草木樨中华根瘤菌CHW10B)和丛枝菌根真菌(缩球囊霉)具有协同作用,两者同时接种可显著提高南方红豆杉根际土壤微生物数量及土壤酶活力,提高土壤微生物碳源利用率和土壤肥力,增加土壤中的生物多样性,从而达到间接促进宿主植物南方红豆杉生长的目的。     

The cation-efflux transporter BjCET2 mediates zinc and cadmium accumulation in <Emphasis Type="Italic">Brassica juncea</Emphasis> L. leaves

Brassica juncea L. is a Zn/Cd accumulator. To determine the physiological basis of its metal accumulation phenotype, the functional properties and role of the metal efflux transporter BjCET2 were investigated using transgenic technology. Heterologous expression of BjCET2 in the double mutant yeast strain Δzrc1Δcot1 enhanced the metal tolerance of the yeast strain and led to decrease in Zn or Cd accumulation. Detection of green fluorescence from green fluorescent protein (GFP) in the root tip of transgenic tobacco further revealed that BjCET2::GFP is localized at the plasma membrane. Semi-quantitative RT-PCR analysis showed that BjCET2 was most abundant in the root and was weakly expressed in the stem and leaves. The expression of BjCET2 was up-regulated by heavy metals. However, exposure to low temperature, salt and drought did not affect the expression of BjCET2. Overexpression of BjCET2 in transgenic B. juncea plants conferred heavy metal tolerance and increased Cd/Zn accumulation in the leaves. BjCET2-deficient B. juncea mediated by antisense RNA resulted in hypersensitivity to heavy metals and decreased Zn/Cd accumulation in the plants. These results suggest that the heavy metal efflux of BjCET2 plays important roles in the metal tolerance of B. juncea and in Zn/Cd accumulation in B. juncea.