Alleviation of Cadmium Adverse Effects by Improving Nutrients Uptake in Bitter Gourd through Cadmium Tolerant Rhizobacteria

Cadmium is acute toxicity inducing heavy metal that significantly decreases the yield of crops. Due to high water solubility, it reaches the plant tissue and disturbs the uptake of macronutrients. Low uptake of nutrients in the presence of cadmium is a well-documented fact due to its antagonistic relationship with those nutrients, i.e., potassium. Furthermore, cadmium stressed plant produced a higher amount of endogenous stress ethylene, which induced negative effects on yield. However, inoculation of 1-amino cyclopropane-1-carboxylate deaminase (ACCD), producing plant growth promoting rhizobacteria (PGPR), can catabolize this stress ethylene and immobilized heavy metals to mitigate cadmium adverse effects. We conducted a study to examine the influence of ACCD PGPR on nutrients uptake and yield of bitter gourd under cadmium toxicity. Cadmium tolerant PGPRs, i.e., Stenotrophomonas maltophilia and Agrobacterium fabrum were inoculated solely and in combination with recommended nitrogen, phosphorus, and potassium fertilizers (RNPKF) applied under different concentration of soil cadmium (2 and 5 mg kg−1 soil). Results showed that A. fabrum with RNPKF showed significant positive response towards an increase in the number of bitter gourds per plant (34% and 68%), fruit length (19% and 29%), bitter gourd yield (26.5% and 21.1%), N (48% and 56%), and K (72% and 55%) concentration from the control at different concentrations of soil cadmium (2 and 5 mg kg−1 soil), respectively. In conclusion, we suggest that A. fabrum with RNPKF can more efficaciously enhance N, K, and yield of bitter gourd under cadmium toxicity.

Mango malformation: A fungal disease, physiological disorder or malady of stress

Mango (Mangifera indica L.) is one of the important commercial crops occupying a prominent place among various fruit crops. Mango malformation is a crucial malady in mango production leading to heavy economic loss. Malformation occurs in vegetative as well as floral tissue, later being virulent leading to loss of entire crop. Fusarium moniliforme is suggested as dominant causal agent of the disease although association of ‘stress ethylene’ with disease occurrence has also been studied. Fungal pathogens responsible for the malady are known to elevate the level of ‘stress ethylene’ in malformed plants. Various reports have been put forward to explain the etiology and control measures of the disease but nature and management of the disease is still a mystery. Hence, the present review aims at offering information regarding aspects of development and management of mango malformation.