Antixenosis and antibiosis mechanisms of resistance to pod borer, <Emphasis Type="Italic">Helicoverpa armigera</Emphasis> in wild relatives of chickpea, <Emphasis Type="Italic">Cicer arietinum</Emphasis>

The noctuid pod borer, Helicoverpa armigera is one of the most damaging pests of chickpea, Cicer arietinum. The levels of resistance to H. armigera in the cultivated chickpea are low to moderate, but the wild relatives of chickpea have exhibited high levels of resistance to this pest. To develop insect-resistant cultivars with durable resistance, it is important to understand the contribution of different components of resistance, and therefore, we studied antixenosis and antibiosis mechanisms of resistance to H. armigera in a diverse array of wild relatives of chickpea. The genotypes IG 70012, PI 599046, IG 70022, PI 599066, IG 70006, IG 70018 (C. bijugum), ICC 506EB, ICCL 86111 (cultivated chickpea), IG 72933, IG 72953 (C. reticulatum), IG 69979 (C. cuneatum) and IG 599076 (C. chrossanicum) exhibited non preference for oviposition by the females of H. armigera under multi-choice, dual-choice and no-choice cage conditions. Based on detached leaf assay, the genotypes IG 70012, IG 70022, IG 70018, IG 70006, PI 599046, PI 599066 (C. bijugum), IG 69979 (C. cuneatum), PI 568217, PI 599077 (C. judaicum) and ICCW 17148 (C. microphyllum) suffered significantly lower leaf damage, and lower larval weights indicating high levels of antibiosis than on the cultivated chickpea. Glandular and non-glandular trichomes showed negative correlation with oviposition, while the glandular trichomes showed a significant and negative correlation with leaf damage rating. Density of non-glandular trichomes was negatively correlated with larval survival. High performance liquid chromatography (HPLC) fingerprints of leaf surface exudates showed a negative correlation of oxalic acid with oviposition, but positive correlation with malic acid. Both oxalic acid and malic acid showed a significant negative correlation with larval survival. The wild relatives exhibiting low preference for oviposition and high levels of antibiosis can be used as sources of resistance to increase the levels and diversify the basis of resistance to H. armigera in cultivated chickpea.     

Response of baby corn genotypes to soil and foliar nitrogen application schedule

Responsive genotypes, timing and mode of nitrogen application are important for realizing potential yield of winter baby corn. Soil application of nitrogen is a common practice. Foliar application enhances absorption and utilization of nitrogen particularly after anthesis. We investigated combined approach in management of nitrogen for the first time including soil applications followed by foliar urea spray to enhance baby corn yield and profitability. To determine these, 2-year study conducted with three genotypes and six schedules of recommended dose of nitrogen (RDN). Growth characters, productivity traits, harvest period and yields recorded. Nitrogen content and uptake, protein content and harvest were determined. Genotype HM-4 produced 4.6% and 4.1% more cobs and corn weight over HQPM-1. Combined approach resulted higher yield attributes, yields, N uptake, protein harvest and monetary returns. RDN in 4 splits with more basal (B) dose increased cob and corn yield by 4.8% and 5.1% than 3 splits (50% B). Results suggest that HM-4 be grown using RDN 50% as B, 25% at knee height stage, 20% at tassel emergence followed by 5% foliar spray after first picking as urea solution (3%) for achieving higher yield and net returns. More studies needed under diverse conditions.     

Ethnobotanical studies of the dwindling aboriginal Jarawa tribe in Andaman Islands,India

World over the traditional knowledge has always formed the foundation for development of modern medicines as a result of scientific follow up of the traditional knowledge. Andaman archipelago represents one of the greatest emporia of ethno botanical wealth in India where aboriginal native tribes of ancient culture remain in their virginity and possess abundant ethnic knowledge. The Jarawas of Andaman Island are one such primitive and dwindling community. Jarawas inhabit the Jarawa Reserve located along the western parts of the South and Middle Andamans. A brief account of anthropology of the tribe is given. Results of ethnobotanical studies of Jarawa tribe have been enumerated which revealed interesting plants which can be further prioritized for scientific evaluation and Bioprospection for product development. The species like Alpinia manii, Amomum aculeatum, belonging to Zingiberaceae and Pseuduvaria prainii, Orophea katschallica of Annonaceae are shown to have effective insect and bee repellent properties. Such leads should be subjected to further scientific scrutiny for development of global level products having mosquito and other disease causing insect repellent properties. While this achieves the human welfare aspects, at the same time boosts the economy of the region. The Jarawas possess extensive knowledge of the plants of the surrounding forests and use them in their daily life for food, medicine, shelter, fibres, ornaments, bows and arrows and for many other needs. Such plants are enumerated with correct botanical names, family, Jarawa names, plant parts used along with details of use.     

Controlled-environment and field evaluation of heat stress induced genetic variability on translocation efficiency and grain filling traits in rice

Journal of Crop Science and Biotechnology - The grain filling of rice is gets weakened by heat stress due to reduced spike photosynthesis at high temperature stress. An alternate source of carbon...