Rhizobium sp.CCNWYC119: a single strain highly effective as biofertilizer for three different peas (Pigeon pea, Sweet pea and Chick pea)

Abstract

Rhizobium spp. was isolated from root nodules of Pigeon pea (Cajanus cajan L.), Sweet pea (Lathyrus sativus L.), Chick pea (Cicer arietinum L.). The isolates ware rod shaped, aerobic, gram negative, motile and non-spore forming. Isolates were positive to Catalase, Citrate utilization, Urea hydrolysis, Congored, Nitrification, Oxidase, Triple sugar iron and MacConkey agar test. The isolates can ferment all nine sugars. Then, the isolates identified as Rhizobium spp. depending on above results were subjected to 16S rRNA sequencing for further confirmation and identification. Surprisingly, the isolates were same strain or member of same cluster of Rhizobium and identified as Rhizobium sp.CCNWYC119 strain based on 16S rRNA sequence (98% similarity). Then, different parameters of soil quality enrichment and plant growth viz. plant height; weight of pods and seeds; number, fresh and dry weight of nodules were studied to test the efficacy of the isolate as biofertilizer. Here, inoculant of Rhizobium sp. isolated from Pigeon pea was used as biofertilizer. The results showed the significant increase of nodulation, enrichment of soil of rhizosphere, plant growth and yield for all three types of inoculated peas as compared with non-inoculated control peas indicating that the isolated strain could be used as a common efficient biofertilizer for Pigeon pea, Sweet pea and Chick pea. It was also found that the isolate grew optimally at temperature 28°C and pH 7.0. Moreover, the isolate was sensitive to the higher concentration of NaCl (>1%) and to antibiotics- Mecillinam, Ciprofloxacin, Cotrimoxazole, Pefloxacin, Ceftazidime and Tetracycline.