Triadimefon stimulates rooting in bean hypocotyl

Triadimefon, a broad spectrum fungicide and an inhibitor of gibberellic biosynthesis, whitened, thickened, and shortened the roots of bean ( Phaseolus vulgaris L. cv. Spring Green) seedlings and stimulated the development of root primordia along the hypocotyl. In a comparative study, triadimefon, IAA, spermidine, putrescine and spermine all stimulated adventitious root growth, but triadimefon was more effective than the other 4 compounds. Equimolar concentrations of gibberellic acid (GA₃) completely eliminated the stimulatory effect of triadimefon. Stimulation of root development by triadimefon was accompanied by inhibition of ethylene biosynthesis followed by removal of basal dominance and an increase in polyamine levels, both of which occurred after rooting had begun. Although triadimefon was effective in stimulating rooting, its mechanism of action is apparently not mediated via the control of ethylene and polyamine biosynthesis.     

An endogenous growth inhibitor, 3-hydroxy-β-ionone. III. Its longitudinal gradients in the first internode of Phaseolus vulgaris

Dark-grown, 10-day-old bean seedlings (Phaseolus vulgaris L. cv. Morocco) were transferred to continuous light, and the resulting changes in growth rate and concentration of 3-hydroxy-β-ionone, an endogenous growth inhibitor, were monitored. The growth rate of the first internodes of the seedlings decreased rapidly and leveled off 20 h after onset of light. This plateau value was about 25% of the growth rate of the non-irradiated control. The concentration of 3-hydroxy-β-ionone in the internodes of the irradiated seedlings increased rapidly and reached a plateau value after 16 h. This increased level of the inhibitor was about 5 times the level in the non-irradiated control. The changes in the levels of the inhibitor in the internodes reflected the light-induced growth inhibition of the internodes. The longitudinal distribution of the growth inhibitor along the first internodes of the seedlings was closely correlated with the light-induced growth inhibition of the corresponding region of the internodes. The present results suggest that the endogenous growth inhibitor 3-hydroxy-β-ionone may play an important role in the inhibition by light of internode growth of bean seedlings.     

廉价蛋白源在草鱼中的应用

用啤酒糟、棉籽饼与菜籽饼等廉价蛋白源作为草鱼的饲料主要蛋白源,与用鱼粉和豆饼作为饲料主要蛋白源进行对比研究。实验结果显示:用鱼粉和豆饼喂养的草鱼比用廉价蛋白源喂养的草鱼生长较快,但廉价蛋白源有降低鱼肝脏脂肪含量的作用。     

大明绿系选后代遗传多样性与高产特征分析

以内蒙古中东部地区61份绿豆品种大明绿系选后代为研究材料,通过对农艺性状的多样性及通径分析,明确了后代品系遗传类型及高产群体性状特征。结果表明,大明绿后代品系间性状差异显著,单株荚数变异系数最大为31.61%,其次为单株粒重28.05%,遗传多样性较丰富,多样性指数为单株荚数2.02,每荚粒数2.01,百粒重1.89,单株粒重1.96。后代品系主要有6种类型,各性状对单株粒重影响大小依次为:单株荚数>每荚粒数>百粒重>节数>株高。高产类型品系主要特征指标为单株粒重超过15 g,单株荚数超过30荚,每荚粒数8~10粒,株高48~60 cm,节数9~10节,百粒重可根据不同需求制定标准。     

Caffeic acid inhibits in vitro rooting in mung bean [Vigna radiata (L.) Wilczek] hypocotyls by inducing oxidative stress

Caffeic acid (CA), which is ubiquitously present in plants, is a potent phytotoxin affecting plant growth and physiology. The aim of our study was to investigate whether CA-induced inhibition of adventitious root formation (ARF) in mung bean {Vigna radiata (L.) Wilczek [Phaseolus aureus Roxb.]} involves the induction of conventional stress responses. The effect of CA (0–1000 μM) on ARF in mung bean was determined by measuring the generation of reactive oxygen species (ROS) in terms of malondialdehyde and hydrogen peroxide (H₂O₂) content, root oxidizability and changes in levels of antioxidant enzymes. Our results show that CA significantly enhanced MDA content, indicating severe lipid peroxidation, and increased H₂O₂ accumulation and root oxidizability in the lower rooted hypocotylar region (LRHR) of mung bean, thereby inducing oxidative stress and cellular damage. In response to CA, there was a significant upregulation in the activities of scavenging enzymes, such as superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, catalase and glutathione reductase, in LRHRs of mung bean. Based on these results, we conclude that CA inhibits ARF in mung bean hypocotyls by inducing ROS-generated oxidative stress and upregulating the activities of antioxidant enzymes.     

Basal Application of Zinc to Improve Mung Bean Yield and Zinc-Grains Biofortfication

Worldwide, the dietary deficiency of zinc (Zn) is prevailing in almost all arid and semi-arid regions. Zinc deficiency is not only the major constraint of lower yield, but also dietary Zn deficiency in cereals grains may cause increasing malnutrition and chronic health problems in human. Exogenous application of Zn through basal soil nutrition might be a useful option to recover Zn deficiency in mung bean. Therefore, field study was conducted to optimize the optimum level and method of Zn nutrition to enhance crop yield and Zn biofortification of mung bean through basal application. Zinc was applied at 0, 5, 10 and 15 kg/ha as basal application and side dressing, and in combination (50% basal application + 50% side dressing). The results highlighted that Zn nutrition prominently improved the mung bean yield as compared with control (no Zn applied). The maximum grains yield and Zn concentration in grains were obtained where Zn was applied at 15 kg/ha as basal application as compared with all other combinations. Better improvement in grain yield was due to significant increase in more number of pods and grain size owing to welldeveloped root system, improved leaf area index and high chlorophyll contents in mung beans leaves. Amongst all applied Zn nutrition’s the basal application of Zn (15 kg/ha) was a viable option to get higher yield and Zn biofortification of mung bean.     

Root rot disease incidence and severity on some legume species grown in Samsun and the fungi isolated from roots and soils

Abstract

Root rot disease is very common in the bean, soybean, faba bean and pea plants growing areas in Samsun province. Disease incidence and severity were detected the highest at 93.8% and 55.4% in the bean growing area, and the lowest at 64.0% and 24.3% in the faba bean growing area respectively. In this study, a total of 2714 fungal isolates were obtained from some legume plants and soil samples. The most common fungi isolated from root and soil samples were Fusarium spp., multinucleate Rhizoctonia (MNR), binucleate Rhizoctonia (BNR) and Pythium spp. respectively. Fusarium spp. were isolated at high rates from all the examined areas. MN Rhizoctonia and BN Rhizoctonia were isolated both from inner and coastal areas of the province, whereas Pythium spp. were isolated in costal areas, except for the Vezirköprü district which is situated in the inner area. When looking at the interactions among pathogens causing root rot, it was found the great majority of the samples (30.4%) isolated both Fusarium spp. and MNR-BNR group fungi, whereas Fusarium spp. and Pythium spp. were isolated together from 10.9% of the samples and MNR-BNR and Pythium spp. from only 1.5% of the samples.     

Independence of genetic variation between circadian rhythm and development time in the seed beetle, Callosobruchus chinensis

A positive genetic correlation between periods of circadian rhythm and developmental time supports the hypothesis that circadian clocks are implicated in the timing of development. Empirical evidence for this genetic correlation in insects has been documented in two fly species. In contrast, here we show that there is no evidence of genetic correlation between circadian rhythm and development time in the adzuki bean beetle, Callosobruchus chinensis. This species has variation that is explained by a major gene in the expression and period length of circadian rhythm between strains. In this study, we found genetic variation in development time between the strains. The development time was not covaried with either the incidence or the period length of circadian rhythm among the strains. Crosses between strains suggest that development time is controlled by a polygene. In the F₂ individuals from the crosses, the circadian rhythm is attributable to allelic variation in the major gene. Across the F₂ individuals, development time was not correlated with either the expression or the period length of circadian rhythm. Thus, we found no effects of major genes responsible for variation in the circadian rhythm on development time in C. chinensis. Our findings collectively give no support to the hypothesis that the circadian clock is involved in the regulation of development time in this species.