Kacou Antoine Alban M.B.,ICAR Central Plantation Crop Research Institute |
Elain Apshara S.,ICAR Central Plantation Crop Research Institute |
Hebbar K.B.,ICAR Central Plantation Crop Research Institute |
Mathias T.G.,Center National Of Recherche Agronomique Cnra |
Severin A.,Félix Houphouët-Boigny University
Indian Journal of Plant Physiology | Year: 2016
Cocoa (Theobroma cacao L.) is sensitive to water deficit stress which is the main factor limiting its productivity. Morpho-physiological responses of cocoa hybrids to differential water deficits at young age showed significant differences under controlled condition. Physiological parameters, viz., water status, gas exchange, photosynthesis and photochemical activities, despite having good correlation among them, may not contribute as selection criteria separately. However, simultaneously they distinguished the hybrids under induced water stress. Three different behavioral groups were categorized, the first group showed small reduction in photosynthesis, followed by maintenance of water use efficiency with low conductance and low transpiration rate in the hybrids VTLCP-22, VTLCP-24 and VTLCH-4. The second group included hybrids VTLCP-27, VTLCP-25 and VTLCP-26, which had adequate functioning of PSII, net photosynthetic activity, reduced transpiration rate, high stomatal resistance and vegetative vigor. Third group comprising of hybrids VTLCH-3, VTLCP-11, VTLCP-28 and VTLCP-29 has high transpiration rate, reduction of PSII photochemical activity and low CO2. Cocoa exhibited significant genotypic variation with physiological parameters at young age and breeding for these traits may improve the performance and sustainability under specific growing conditions. © 2015, Indian Society for Plant Physiology.
Shareefa M.,ICAR Central Plantation Crop Research Institute |
Thomas R.J.,ICAR Central Plantation Crop Research Institute |
Nampoothiri C.K.,ICAR Central Plantation Crop Research Institute |
Karun A.,ICAR Central Plantation Crop Research Institute
Indian Journal of Horticulture | Year: 2014
Vivipary is a problem in some dwarf varieties of coconut as their seed nuts show low germination compared to Talls. An experiment was carried out to study the extent of vivipary in dwarf coconut varieties (MGD, MYD, MOD and CGD) with WCT as control. Observations on nut traits like shape, colour, length, weight and water content of the seed nut, thickness, weight and polyphenol content of the husk, length and weight of embryo, TSS of nut water were recorded from 10-, 11- and 12-month-old nuts of each variety. Observations were also recorded at bimonthly intervals during November 2011-September 2012. None of the ten-month-old seed nut exhibited vivipary. However, few 11th old MOD nuts (3%) harvested during November showed vivipary. The results showed that the extent of vivipary was highest during September and least during January. Among the varieties, MYD exhibited maximum vivipary (24%) followed by MOD and MGD (16%) and the least was in WCT (0.6%). Vivipary was negatively correlated with various nut characters, husk thickness and weight. However, prevailing climatic conditions like amount of rainfall, number of rainy days and relative humidity during the preceding 30-day of harvest had significant positive correlation with vivipary. It is suggested that vivipary in dwarf varieties can be avoided by harvesting the seed nuts at the proper stage. © 2015, Horticulture Society of India. All rights reserved.
Khadke G.N.,ICAR Central Plantation Crop Research Institute |
Hima Bindu K.,ICAR Central Plantation Crop Research Institute |
Motcha Anthony Reetha B.,ICAR Central Plantation Crop Research Institute |
Suryanarayana M.A.,ICAR Central Plantation Crop Research Institute |
And 2 more authors.
Indian Journal of Horticulture | Year: 2015
Investigations on the levels and distribution of genetic variability are essential for conservation and genetic improvement programme. Genetic diversity analysis was carried out in 37 accessions of betelvine and two accessions of P. hamiltoni and one of P. colubrinum using inter simple sequence repeats (ISSR) markers. Out of 60 ISSR primers tested, 15 were selected based on high and consistent polymorphism. They generated a total 82 bands of which 72 were polymorphic. The different band statistics and efficiency parameters showed that the primers, viz., UBC-822, 825, 826, 863 and ISSR-1, ISSR-15 were more efficient to study the genetic diversity. The UPGMA dendrogram and PCA plot revealed P. colubrinum to be the most distant of the three species. The accessions from Andaman clustered based on geographical origin and shared 70% similarity. A distinct genderbased clustering was observed among cultivated clones of betelvine. © 2015, Horticulture Society of India. All rights reserved.