Ishfaq Ahmad Hafiz

Review: role of carbon sources for in vitro plant growth and development

In vitro plant cells, tissues and organ cultures are not fully autotrophic establishing a need for carbohydrates in culture media to maintain the osmotic potential, as well as to serve as energy and carbon sources for developmental processes including shoot proliferation, root induction as well as emission, embryogenesis and organogenesis, which are highly energy demanding developmental processes in plant biology. A variety of carbon sources (both reducing and non-reducing) are used in culture media depending upon genotypes and specific stages of growth. However, sucrose is most widely used as a major transport-sugar in the phloem sap of many plants. In micropropagation systems, morphogenetic potential of plant tissues can greatly be manipulated by varying type and concentration of carbon sources. The present article reviews the past and current findings on carbon sources and their sustainable utilization for in vitro plant tissue culture to achieve better growth rate and development.

In vitro propagation of orchid ( Dendrobium nobile ) var. Emma white

-1 increased the rooting percentage (97.5%) number of roots (4.70) and root length (3.47 cm) more efficiently than NAA. Higher concentrations of IBA and NAA (3.0 mg l -1 ) showed poor results of rooting.

Interaction of callus selection media and stress duration for in vitro selection of drought tolerant callus of wheat

Callus culture is a novel approach addressing cultured cells as selection units independent of whole plant. Natural variations for drought tolerance existing among cell lines can be exploited in vitro in the presence of suitable concentration of osmoticum and stress duration. The study was aimed to standardized callus selection media and culture duration to select drought tolerant cell line (callus) of wheat. Calli were induced from immature embryos on Murashige and Skoog (MS) based medium supplemented with 4 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D). Proliferated calli were cultured on various callus selection medias (MS based media + 30 g/L sucrose + 6 g/L agar + 4 mg/L 2,4-D + various levels of polyethylene glycol-600 (PEG-6000) induced osmotic stress including -0.3, -0.6, -0.9 or -1.2 MPa along with control, that is, 0.0 MPa) for two, three or four weeks. Callus health, callus growth rate, callus survival (%) and regeneration (%) declined significantly on media supplemented with higher levels of PEG-6000 induced osmotic stress and with increasing stress duration. Not a single callus could survive nor regenerate on selection media comprising PEG-6000 induced osmotic stress of -1.2 MPa imposed for four weeks. The highest callus growth rate (CGR) was recorded on PEG-6000 free media when calli were cultured for four weeks (-7.32%) on the media supplemented with PEG-6000 induced osmotic stress of -1.2 MPa. Callus selection media comprising PEG-6000 which induced osmotic stress of -0.9 MPa for four weeks was found selective and sub-lethal for wheat calli with 8.63% CGR, 26.62% callus survival and 21.50% regeneration; and seemed ideal for screening drought tolerant somaclonal cell lines of wheat.

Encapsulated calcium carbide enhances production and postharvest performance of potato (Solanum tuberosum) tubers

Abstract The effect of encapsulated calcium carbide (CaC2; ECC at 30, 60, 90, and 120 kg ha−1) on pre‐harvest production and postharvest performance of potato (Solanum tuberosum) hybrid variety ‘Sante’ was studied. The ECC was applied twice in the root zone at the time of sowing and 2 weeks after sowing. The data on the parameters — number of days required for sprouting; sprouting percentage; plant height; number of leaves per plant; leaf area; photosynthesis rate; number of stems per plant; number, size, and weight of tubers; yield; weight loss; shriveling percentage; and sprout percentage were recorded. The results indicated that the number of days required for sprouting of tubers and plant height was reduced significantly by the application of ECC compared with the control. Furthermore, ECC at 60 kg ha−1 significantly reduced the number of days required for sprouting and plant height compared with other treatments. Sprouting percentage, number of leaves per plant, leaf area, photosynthesis rate, and number of stems per plant significantly increased by the application of ECC at 60 and 90 kg ha−1. Weight, size of tubers, and overall yield of tubers was also increased significantly with the application of ECC at 60 kg ha−1. In conclusion, the application of CaC2 at 60 kg ha−1 in the root zone increased vegetative growth, total weight, number of large tubers, and increased total yield (40–50%).

Evaluation of seed priming on germination of Gladiolus alatus

Seed priming improves seed performance under environmental conditions. The study was designed to evaluate the effect of different priming treatments on germination behavior of Gladiolus alatus. The experiment was conducted under complete randomized design (CRD) with four replications. Seed priming was done with different concentration of potassium nitrate (KNO 3 ) and hydropriming. All the treatments had significant effect on germination percentage, germination test in growth room, time for 50% germination and mean germination time. Results show that maximum invigoration was observed in seeds osmoprimed at lower concentrations of KNO 3 and with hydropriming while minimum invigoration was observed at higher concentration of KNO 3- . It was concluded that germination percentage can be increased by using lower concentrations of KNO 3 and with hydropriming. Key words: Priming, hydropriming, gladiolus, germination.

Effect of pre-harvest foliar application of amino acids and seaweed (Ascophylum nodosum) extract on growth, yield, and storage life of different bell pepper (Capsicum annuum L.) cultivars grown under hydroponic conditions

Abstract The study was set up to evaluate the efficiency of amino acids and seaweed on vegetative growth, reproductive phase, yield, and postharvest storage quality of hydroponically grown bell pepper cultivars “Sven Rz F-1” and “Red Knight.” Different concentrations of amino acid and seaweed were sprayed on bell pepper plants under hydroponic conditions. Pre-harvest foliar application of amino acids and seaweed significantly increased plant height, number of leaves, leaf area, yield per plant, number of marketable fruits per plant, average fruit diameter, fruit wall thickness, and average single fruit weight. Amino acid and seaweed significantly improved postharvest physicochemical quality of both bell pepper cultivars under extended cold storage conditions. Conclusively, amino acid as well as seaweed extract not only improved growth, development, yield, and overall quality of bell pepper cultivars but also increased storage life with reduced weight loss and decay along with better physicochemical quality.