[en] The present study was carried out to investigate the physiological (relative water content) pod dry weight, pods plant/sup -1/, pod yield (kg plot/sup -1/), shelling (%), plant height and biochemical (endogenous ABA level) traits of peanut cultivar Swat Phalli-96 under drought stress. The result showed that drought stress significantly (p<0.05) reduced relative water content (RWC), pod dry weight, pods plant/sup -1/, pod yield (kg plot/sup -1/), shelling (%) and plant height. GA and IAA applied as seed treatment or foliar spray had no significant (p >0.05) effect on various parameters under drought stress conditions. However, foliar application of ABA (10/sup -4/ M) partially ameliorated the adverse effects of drought stress on growth and yield components. Foliar application of ABA to plants when subsequently exposed to drought stress resulted in elevated levels of endogenous ABA. The endogenous ABA levels in shoot increased earlier in response to applied ABA than that of root. (author)

[en] Studies were initiated to explore the role of plant growth regulators and explant types on efficient plantlets regeneration via direct and indirect organogenesis in Kinnow mandarin [Citrus reticulata L. (Blanco)]. Explants were cultured on MS medium containing varying concentrations of phytohormones. The best callus induction response was obtained in MS medium containing 5 mg/l 2,4-D and 1 mg/l BAP where 90% from nucellus tissue, 58% from shoot apical meristem and 56% from nodal segments explants showed callogenic response after 2 weeks of inoculation.Best shoot induction medium via indirect organogenesis was found for nucellus tissue when MS medium was supplemented with 1.5 mg/l Kin and 500 mg/l malt extract which was 46% whereas for SAM and nodal segments, best response was obtained when MS medium was supplemented with BAP and NAA (3.0 + 0.5) mg/l which was 40% and 48% from SAM and nodal segments respectively after 11 weeks of inoculation.The shoot induction as well as multiplication were also studied by using different combinations and different concentrations of phytohormones in growth medium. The best medium for shoot induction percentage via direct organogenesis was [M3= MS + BAP (1.0 mg/l)] whereas 92%, 90% and 82% from nucellus tissue, SAM and nodal segments respectively showed organogenic response after 4 weeks of inoculation, whereas maximum number of shoots per explants was obtained in medium (M9)containing MS + Kin where 4, 7 and 6 average number of shoots were obtained from nucellus tissue,SAM and nodal segments respectively after 11 weeks of inoculation.Best rooting medium was found when MS medium was supplemented with 2 mg/l NAA where 88% from nucellus tissue and 80% from the nodal segments showed rooting response whereas for SAM best rooting response was obtained when supplemented with 1.5 mg/l NAA i.e 78%. The plantlets were successfully acclimatized in different potting mixtures and highest survival rate (100%) was achieved in potting mixture containing sand and peat moss (2:1). (author)

[en] Two products (in solution state) namely plant growth promoter from brown seaweed (alginate) and plant protector from shrimp shell (chitosan) have been produced by the application of radiation processing technology. By foliar spraying, the irradiated alginate impacts the remarkable increase of the productivity of plant such as carrot, cabbage, onion, and the irradiated chitosan exhibits not only protection effect with highly antifungal activity but also growth promotion effect for plants. (author)

[en] Chemical inhibitors of pollen development having a phenylcinnoline carboxylate structure were found to inhibit IAA- and 1-NAA-induced growth in maize coleoptile sections. The inhibitor (100 μM) used in these experiments caused approx. 35% reduction in auxin-induced growth over the auxin concentration range of 0.3 to 100 μM. Growth inhibition was noted as a lengthening of the latent period and a decrease in the rate of an auxin-induced growth response. An acid growth response to pH 5 buffer in abraded sections was not impaired. The velocity of basipetal transport of [³H]IAA through the coleoptile sections also was not inhibited by the compound, nor was uptake of [³H]IAA. Similarly, the inhibitor does not appear to alter auxin-induced H⁺ secretion. We suggest that the agent targets some other process necessary for auxin-dependent growth

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[en] With the help of radiation induced early and late flowering mutantlines of jute, studies have been made to determine the biochemical factors which could regulate the induction and expression of genes for the flowering processes in this plant. Comparative biochemical investigations were done with the parameters like : plant pigments (Chlorophyl a, b and carotenoides), auxin/antiauxin, and gibberellin/anti-gibberellin type of substances. Quantitative as well as qualitative differences of plant pigments were observed between the early and late flowering lines. Extracts of early flowering lines have been found to induce earliness in the late flowering mother variety of jute (D-154). Re-isolated growth inhibitors of early flowering lines have also been found to induce earliness in the late flowering mother variety (D-154). (author)

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[en] The various endogenous hormones of apple trees were analysed by the RIA method. The results indicated that one of the mechanisms of promoting the flower bud differentiation with Ethrel, PP333 and summer pruning was making a beneficial hormonal status to flower bud differentiation in the shoot tips during the physiological initiation period, e.g. the content of cytokinins and endogenous ethylene were higher, the ABA was just in right amount and the promotive growth hormones (IAA and GA₃) decreased

[en] Carrageenans were irradiated in solid state to doses 50-1000 kGy in air at ambient temperature. Changes in their molecular weight and functional properties with respect to their FT-IR and UV spectra were evaluated. Irradiation of carrageenans resulted in a rapid decrease of molecular weight indicating main chain scission in their polymeric structures. Formations of some compounds were evident by new absorption peaks in their UV and FT-IR spectra and quantitative analyses of the FT-IR spectra which, in addition, support that there is a breakdown in the carrageenan structure. Irradiated carrageenans were investigated for their plant growth promoting activities. Carrageenans were added to the nutrient solutions for rice seedlings under non-circulating hydroponics cultivation. Irradiated carrageenan induced weight gain in treated rice seedlings. Maximum weight gain was obtained with KC irradiated at 100 kGy while treatment with IC at 500 kGy. IC exhibited less growth promoting properties than KC. The growth of fungi on the roots disappeared with treatment of IC and KC irradiated at 500 kGy. Growth promotion of some leafy vegetables was also observed with application of degraded KC. The carrageenan molecule has been broken down to smaller molecule(s) or compound(s) that can be absorbed effectively as nourishment factors and anti-microbial agents by plants. (author)