K. G. Vijay Anand

In vitro plant regeneration of non-toxic Jatropha curcas L.: Direct shoot organogenesis from cotyledonary petiole explants

Jatropha curcas, the energy plant has attained great attention in recent years because of its biodiesel production potential; however, oil and deoiled cakes are toxic. A non-toxic variety of J. curcas is reported from Mexico. A simple and efficient protocol has been developed for plant regeneration using cotyledonary petiole explants of non-toxic variety of J. curcas. The percentage of induction of shoot buds (59.11%), and the number of shoot buds (5.01) per explant was achieved on Murashige and Skoog’s (MS) medium supplemented with 2.27 μM thidiazuron (TDZ). These induced shoot buds multiplied when subcultured on MS medium supplemented with 10 μM kinetin (Kn), 4.5 μM 6-benzyl aminopurine (BAP), and 5.5 μM α-naphthaleneacetic acid (NAA) for 4 weeks and subsequent elongation achieved on MS medium supplemented with 2.25 μM BAP and 8.5 μM indole-3-acetic acid (IAA). Shoots more than 2 cm long were harvested and cultured on MS medium containing different concentrations and combinations of IBA, IAA, NAA, and 0.25 mg L−1 activated charcoal, and 19.91% rooting was achieved in 15 μM IBA, 5.7 μM IAA, and 16.5 μM NAA after 4 weeks with more than 90% survival rate.

Drought alleviatory potential of Kappaphycus seaweed extract and the role of the quaternary ammonium compounds as its constituents towards imparting drought tolerance in Zea mays L.

Kappaphycus seaweed extract (KSWE) has been reported to enhance the yield of several crops under normal conditions. The detection of the quaternary ammonium compounds (QACs) glycine betaine and choline chloride (GBCh) in KSWE impelled us to explore its efficacy on growth and yield under soil moisture deficit conditions. Another objective was to elucidate the extent to which the QACs have a role in mitigating drought stress, if at all. Thus, a factorial experiment was carried out on maize plants, wherein five foliar treatments (KSWE at 10 and 15%; GBCh at equivalent concentration to that found in 10 and 15% KSWE, respectively, designated as 10 and 15% Eq-GBCh; and water spray control) were subjected to three soil moisture stress levels (well-watered, WW; moderately stressed, MS; and severely stressed, SS). Observations were recorded for growth and yield parameters, pigments, photosynthetic attributes, antioxidant enzymes, and quality of grains. The results revealed the ability of KSWE to alleviate soil moisture stress, 10% KSWE being effective in increasing the seed yield under WW and MS conditions while 15% being optimal under SS condition. The percent increases in seed yield over their respective controls under WW, MS, and SS conditions at the optimal KSWE concentrations were 13.5, 21.7, and 36.4%, respectively, indicating higher grain yield response to KSWE treatments at higher stress levels. The yield advantage under stress could be attributed to minimal damage of photosystem in KSWE-treated plants as evidenced by higher pigment content, photosynthetic rate, reduced photoinhibition, and lipid peroxidation by enhanced protection against reactive oxygen species. The protein content in grains was enhanced by KSWE application under all stress groups compared to their respective controls. Although the predominant role of GBCh in KSWE towards drought mitigation and yield response was apparent, the results also connoted towards the role of other constituents in KSWE acting in unison along with GBCh, which should be investigated further.

Evaluation of Fertilizer Potential of Different K Compounds Prepared Utilizing Sea Bittern as Feed Stock

Aim: Many countries import potassic fertilizers due to dearth of K-mineral deposits. Therefore processes to obtain K-nutrient sources from sea bittern were developed by our Institute. The present investigation evaluated the fertilizer potential of three different sea bittern-derived (SBD) potassium forms developed viz., potassium schoenite, potassium nitrate and potassium ammonium sulfate on maize productivity in two cropping seasons. Methods: The pot and field experiments consisted of four treatments, wherein the three K forms were applied at the recommended rate of 40 kg K2O ha−1 and were compared with commercially used sulfate of potash. The effect of these fertilizers on different parameters of plant and soil were evaluated. Results: The application of SBD-potassic fertilizers led to enhancement in growth, productivity and quality of maize which related well with higher photosynthesis, nutrient uptake and soil quality parameters. On an average all the three forms of sea bittern-derived potash enhanced yield of maize over control by 22.3 and 23.8%, respectively, in pot and field trials. The best performance was under SBD-KNO3, which also recorded the highest benefit: cost ratio of 1.76. Conclusion: The K-fertilizers derived from sea-bittern—a waste product of salt industry—can thus be economically used to improve crop production sustainably.