Browsing by Author "Binu N Kamalolbhavan"

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Genetic variability and plus tree selection in natural populations of Malaveppu (Melia dubia Cav.)
(Department of Forest biology and tree improvement, Vellanikkara, 2019) Binu N Kamalolbhavan; Santhoshkumar, A V
Progeny testing and genetic diversity analysis in plus trees of Melia dubia Cav.
(Department of Forest Biology and Tree Improvement, College of Forestry, Vellanikkara, 2022) Shifin S Ravuther; Binu N Kamalolbhavan
The present study titled “Progeny testing and genetic diversity analysis in plus trees of Melia dubia Cav.” was carried out from 2020 to 2021 with the objective of progeny evaluation in 25 half sib plus trees identified from different part of Kerala, by studying the growth performance of its seed progeny planted at college of forestry germplasm field. The study also includes exploring the genetic diversity of these 25 plus tree seed progenies along with analysing the caryophyllene content, one of the economically important phytochemical compounds present in M. dubia. The plus tree seed progeny differed significantly in morphological traits like height, collar girth, volume and physiological parameters like photosynthetic and transpiration rate, stomatal conductance, chlorophyll content and relative water content. The progeny FCV-MD-03 of Tholpetty in Wayanad district performed better in growth parameters viz., height (5.61 m), collar girth (0.42 m) and tree volume of (0.017 m3 ). The variability study indicated that the morphological trait (volume) and physiological trait (stomatal conductance) exhibited higher PCV and GCV. From the heritability estimation it was observed that the most heritable morphological trait was collar girth followed by the plant height. For the physiological parameter, transpiration rate (0.91) was the most heritable trait followed by the chlorophyll content. These morphological and physiological traits were positively correlated implicating the significance of physiological parameters as source to identify better progeny. Path analysis on morphological trait has showed that the collar girth had the highest positive direct effect on the plant volume. Genetic variation study in 25 plus tree progenies using ISSR primer produced 164 amplicons which estimates viz., percentage of polymorphism (68%), polymorphism information content (0.70 to 0.83), Nei’s gene diversity (31%). The dendrogram obtained by using UPGMA classified the 25 accession of M. dubia into 2 distinct clusters. Cluster I constitute population from Wayanad and the rest of the 136 population in cluster II. Based on the genetic variation observed, superior seed sources can be identified and tree improvement programme could be developed for the conservation and further development of M. dubia. Standardization of HPLC for the quantification of caryophyllene phytochemical in M dubia was studied. Significant variation was observed for the total caryophyllene content for the different accession of M dubia seed progeny. The maximum quantity was observed in FCV-MD-08 (16.4 %) of Pothundy in Palghat district followed by FCV-MD-3 of Tholpetty in Wayanad.
Response of sandal (Santalum album Linn.) seedlings to shade and mycorrhizal association
(Department of tree physiology and breeding, College of Forestry, Vellanikkara, 2002) Binu N Kamalolbhavan; Ashokan, P K
The occurrence of sandal- Arbuscular Mycorrhizal Fungi (AMF) associations in natural sandal growing forests and the response of sandal seedlings to inoculation with commonly available cultures of AMF, shade levels and nature of hosts were investigated in a pot culture experiment at the College of Forestry, Kerala Agricultural University, Vellanikkara. Two important sandal growing regions in the state, Marayoor (ldukki district) and Wadakancherry (Thrissur district) were selected for this study and a non-sandal growing area in Thrissur district was selected as a control for the soil studies . The result showed that characters like height, number of leaves, leaf area and shoot weight of sandal seedlings increased due to the Arbuscular Mycorrhizal Fungi inoculation and maximum response was observed for seedlings grown in soils inoculated with Glomus mosseae. The characters like collar girth, root weight did not show any significant difference for the mycorrhizal inoculation. It was further observed that the interactions between shade and mycorrhizae were the best under 50 per cent shade level especially for those seedlings inoculated with Glomus mosseae. During the initial seedling phase, high shade (75 per cent) is needed for sandal, but during the later stages of seedling growth, medium shade (50 per cent) resulted in best growth of seedlings. Growth of sandal seedlings with two host species, casuarina and redgram was on par. The relative water content and plant water potential were higher in seedlings inoculated with AMF. The N, P, K content of the shoot of sandal seedlings were maximum for seedlings inoculated with Glomus mosseae. Sandal seedlings collected from natural sandal growmg regions investigated for the presence of sandal-AMF association revealed that the roots of sandal seedlings from Wadakancherry forest showed 33 per cent of colonization, while the seedlings from Marayoor forest showed no colonization. Sandal seedlings grown for four months in the soils collected from these two regions showed superior growth when compared to those seedlings grown in soils from the agricultural lands of Thrissur, but no AMF colonization was observed in the roots of the sandal seedlings .