Cadmium, chromium and copper in greengram plants Parvaze Ahmad Wani, Mohammad Saghir Khan, Almas Zaidi To cite this version: Parvaze Ahmad Wani, Mohammad Saghir Khan, Almas Zaidi. Cadmium, chromium and copper in greengram plants. Agronomy for Sustainable Development, Springer Verlag/EDP Sciences/INRA, 2007, 27 (2), pp.145-153. hal-00886383 HAL Id: hal-00886383 https://hal.archives-ouvertes.fr/hal-00886383 Submitted on 1 Jan 2007 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Agron. Sustain. Dev. 27 (2007) 145–153 145 c INRA, EDP Sciences, 2007 DOI: 10.1051/agro:2007036 Original article Cadmium, chromium and copper in greengram plants Parvaze Ahmad W, Mohammad Saghir K*,AlmasZ Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh – 202 002, U.P., India (Accepted 7 December 2006) Abstract – Soils contaminated with heavy metals including cadmium, chromium and copper present a major concern for sustainable agriculture. We studied the effects of cadmium, chromium and copper used both separately and as mixtures, on plant growth, nodulation, leghaemoglobin, seed yield and grain protein in seeds, in greengram inoculated with Bradyrhizobium sp. (Vigna). Cadmium at 24 mg kg−1 of soil reduced the dry matter accumulation and number of nodules by 27 and 38%, respectively. Chromium at 136 mg kg−1of soil increased the dry phytomass and nodule numbers by 133 and 100%, respectively. The average maximum increase of 74% in seed yield occurred at 136 mg Cr kg−1 of soil. Cadmium and copper at 24 and 1338 mg kg−1 soil decreased the seed yield by 40 and 26%, respectively. Chromium at 136 kg−1 of soil increased the root and shoot N and leghaemoglobin content by 42, 31% and 50%, respectively. In contrast, the root and shoot N decreased by 22% at 24 mg Cd kg−1 of soil, while a maximum decrease of 50% in leghaemoglobin content occurred at 12 and 669 and 24 and 1338 mg Cd with Cu kg−1 of soil, relative to the control. The average maximum grain protein (283 mg g−1) was observed at 136 mg Cr kg−1 of soil, while minimum grain protein (231 mg g−1) was recorded at 24 and 1338 mg kg−1 of cadmium with copper. The metal accumulation in roots and shoots at 50 days after sowing and in grains 80 days after seeding differed among treatments. The degree of toxicity of heavy metals to the measured parameters decreased in the order Cd > Cu > Cr. heavy metals / Bradyrhizobium / greengram / phyto-accumulation 1. INTRODUCTION L.), although it fixed N2 with Trifolium subterraneum (Hirsch et al., 1993). Further studies on sludge field trials in Braun- Greengram [Vigna radiata L. wilczek] is a major grain schweig showed that increasing sludge rates reduced the num- legume and is grown widely in tropical countries. In India, ber of indigenous populations of R. leguminosarum bv. trifolii greengram occupies an area of three million hectares, account- to low, or undetectable levels (Chaudri et al., 1993). The ad- ing for 14% of the total pulses area and 7% of total production verse effects of sludge application on rhizobial species and the ff (Singh et al., 2004). Meanwhile, for production of greengram, concomitant e ect on N2 fixation in faba bean (Chaudri et al., symbiotic nodule bacterium is used either for coating the seeds 2000) and chickpea (Yadav and Shukla, 1983) have been re- or can be directly incorporated into soils in order to enhance ported. There is evidence that suggests that reduction in plant the yield. Although reports of metals on rhizobia are contra- growth, nodule size and nitrogenase activity in white clover dictory, several studies have demonstrated that some of these was due to Cd, Pb and Zn, when plants were grown in soils metals are incompatible with rhizobia (Broos et al., 2005) and highly contaminated with these metals (Rother et al., 1983). legumes (Broos et al., 2004). In a similar study, a pronounced metal toxicity to white clover The toxicity of heavy metals to nitrogen-fixing rhizobia and was confirmed in a sludge-treated soil where N2 fixation was the process mediated by them has been the subject of intense halved by increasing metal concentrations in soil (Broos et al., research. Changes in rhizobial populations due to high concen- 2005). The effect of total metal concentrations on the survival tration of heavy metals, as well as effects of heavy metals on of R. legumnosarum, however, did not occur in soils contam- legume plants, have been documented. The toxicity of heavy inated with cadmium salts or with high Ni/Cd sewage sludge. metals can cause multiple effects on plants. For instance, a Similarly, the sewage sludge, containing a higher concentra- higher concentration of metals may induce interaction with tion of Zn, adversely affected the survival of R. leguminosarum sulfhydryl groups, leading to the inactivation of plant protein bv. trifolii (Broos et. al., 2005). (Assche and Clijsters, 1990). On the other hand, the growth Reports on the toxicity of heavy metals to biological ni- and plant growth-promoting activities of microorganisms can trogen fixation (BNF) are, however, conflicting. Earlier stud- be altered because of a high concentration of metals (Broos ies demonstrated that acetylene reduction activity (ARA) was et al., 2004). strongly affected by heavy metals in mine spoils or in sludge- In one study, only a single strain of Rhizobium legumi- amended soils (Heckman, 1987). In contrast, no significant ff nosarum survived in the metal-contaminated plots, and this adverse e ect of metal-contaminated sludge on N2 fixation strainfailedtofixN2 with white clover (Trifolium repens in white clover was detected (Ibekwe et al., 1995). In a field study, Heckman et al. (1987) failed to detect adverse effects on * Corresponding author: khanms17@rediffmail.com soybean plant growth and BNF in biosolid-amended soils. Article published by EDP Sciences and available at http://www.edpsciences.org/agro or http://dx.doi.org/10.1051/agro:2007036 146 P.A. Wani et al. Though a large number of reports on the effects of sewage sewage-treated soils used in greengram production. The ef- sludge containing multiple metals are available, there is dis- fects of some mixtures were also evaluated (mg kg−1 soil): crepancy in the reported results. Hence, a firm conclusion on cadmium with chromium (6 and 34; 12 and 68; 24 and 136), the toxicity of heavy metals to legumes and their symbiotic cadmium with copper (6 and 334.5; 12 and 669; 24 and 1338), partners cannot be drawn. Moreover, the majority of the ad- and chromium with copper (34 and 334.5; 68 and 669; 136 verse effects have been observed in sludge-treated soils and and 1338). Some pots without metals but inoculated with possibly factors other than metals (e.g. contaminants, excess Bradyrhizobium sp. (vigna) were used as control for compar- N supply) could lead to the increased toxicity. Considering the ison. Fertilizer at 20:40:40 mg kg−1 soil with N as urea, P lack of adequate data and conflicting reports on the effect of as diammonium phosphate and K as potash was dissolved in heavy metals on legumes and nodule bacteria, and the possi- 500 mL water for each pot and added to the soil surface at bility of damage to the crop due to the deposition of heavy the time of sowing in March 2005, and this experiment was metals in the soil, the current study was initiated to examine repeated with the same treatments in March 2006. Ten inoc- the effects of varying levels of cadmium, chromium and cop- ulated seeds were sown in each pot containing 10 kg non- per on greengram. The present study evaluates the effect of sterilized sandy clay loam soil (organic carbon 0.4%, Kjeldahl these metals when used separately and as mixtures, on growth, N0.75gkg−1,OlsenP16mgkg−1, pH 7.2 and water-holding symbiosis, seed yield and grain protein of greengram. In addi- capacity 0.44 mL g−1, Cr 6.3, Cu 12.2, Cd 0.2 µgg−1 of soil). tion, the uptake of these metals by plant tissues and grains was Six pots used for each treatment were arranged in a complete also assessed, when greengram was grown in sandy clay loam randomized design. One week after emergence, the seedlings soils. were thinned to three in each pot. The pots were watered with tap water daily and were maintained in open field conditions. 2. MATERIALS AND METHODS 2.3. Plant growth, nodulation and N content 2.1. Soil analysis for heavy metals All plants in three pots for each treatment were removed The soil samples were collected from Mathura road, 7 km at 50 days after seeding (DAS), and were used for destruc- from Aligarh, Uttar Pradesh, India. There was consistent use tive plant analysis to record nodulation. The roots were care- of industrial sewage water on this soil. The soil samples were fully washed and nodules were detached, counted, oven-dried at 80 ◦C and weighed. Plants uprooted at 50 DAS were oven- collected in polythene bags and were used for heavy metal de- ◦ termination by a flame atomic absorption spectrophotometer dried at 80 C to measure the total plant biomass.