P- ISSN: 0976-1675
E- ISSN: 2249-4538

© CARAS (Centre for Advanced Research in Agricultural Sciences)
NAAS Score: 4.54

Volume - 1 - April-June 2010

Research Journal of Agricultural Sciences
Vol : 1 - Issue : 2 ; 53-65
Samson M . Kamunya*, Francis N. Wachira1, P. Okinda Owuor3, Ram S. Pathak2, John K. Wanyoko*, Ram K. Sharma4 and Richard C. Muoki*
*Tea Research Foundation of Kenya, P. O. Box 820 - 20200, Kericho, Kenya 1Department of Biochemistry and Molecular Biology, 2Department of Crops, Horticulture and Soil Sciences, Egerton University, P.O. Box 536-20115, Njoro, Kenya 3Department of Chemistry, Maseno University, P.O. Box 333-40105, Maseno, Kenya 4Division of Biotechnology, Institute of Himalayan Bio-resource Technology, Post Box 6, Palampur-176 061, (H. P.) India
Abstract
The genetic parameters for eight agronomic and quality traits in tea (Camellia sinensis) were estimated using a 4 x 4 full diallel analysis. There were significant family and clonal variations for the traits among the progenies and their parents. The mid-parent heterosis (MPH) and better-parent heterosis (BPH) averaged across the families, were high for fermentability (MPH: 108.5%; BPH: -12.82), and drought tolerance (MPH: 16.33%; BPH: 2.30%) but low for yield (MPH: 2.17%; BPH: -5.09%) and total polyphenols (MPH: -2.81%; BPH: -5.71%). The heritability estimates for yield (h2 = 0. 44 ± 0.16; H2 = 0.56 ± 0.15), drought tolerance (h2 = 0.61 ± 0.06; H2 = 0.96 ± 0.01) and fermentability (h2 = 0.45 ± 0.04; H2 = 0.98 ± 0.01) were high indicating that the three traits are highly heritable and further hybridization or judicious clonal selection can lead to improvement. Correlations analyses among the traits were significant among drought tolerance and black tea quality, suggesting control by either linked or pleiotropic genes, indicating possibility of simultaneous selection of more than one trait. Moderate genetic gains are achievable from selection based on clonal means for characters that traditionally have received improvement attention like yield and fermentability at 14.1% and 8.9%, respectively, while traits such as drought tolerance and pubescence realized considerable gains at 20.6%, and 30%, respectively. The results emphasize the importance of reliance on genetic parameters for enhanced tea improvement programmes. Selecting mating cultivars with high tolerance to drought, high pubescence and yield could lead to new cultivars with higher economic potentials.

Research Article | Published online : 10-Apr-2010

Research Journal of Agricultural Sciences
Vol : 1 - Issue : 2 ; 66-68
K. Kheradmand, S. A. Sadat Noori* and Gh. Sabahi**
Department of Entomology and Plant Pathology, *Department of Agronomy and Plant Breeding, College of Abouraihan, University of Tehran, Pakdasht, Iran **Department of Plant Protection, College of Agriculture, University of Tehran, Karaj, Iran
Abstract
Essential oils from seeds of jojoba, Simmondasia chinensis (Link) grown in Kerman (South-eastern part of Iran) were obtained by steam distillation, and was used for efficacy on the repellency of two important stored products insects, Oryzaephilus surinamensis Linnaeus (Coleoptera: Cucujidae) and Callosobruchus maculates (Fabricius) (Coleoptera: Bruchidae). The purity of used essential oil was 0.97 and the experiments were done at 0.2 ml concentration at 30 replications, by using y-shape olfactometer and Loschiavo, (1952) methods. Data processing was conducted by the SAS system. The results indicated that the repellency of jojoba oil was 21.41 ± 3.44 and 11.07± 4.01 for C. maculates and 18. 75±0.31 and 12.74±1.28 for O. surinamensis by using y-shape olfactometer and Loschiavo methods, respectively. To compare, no significant differences were observed between the effect of seeds oil on two tested pest species and different methods of experiments. These observations confirmed that the essential oils that are extracted from jojoba leaves have more repellency effectiveness.

Research Article | Published online : 11-Apr-2010

Research Journal of Agricultural Sciences
Vol : 1 - Issue : 2 ; 69-74
Soumik Sarkar, A. Satheshkumar, R. Jayanthi and R. Premkumar
UPASI, Tea Research Foundation, Tea Research Institute, Valparai-642 127, Coimbatore, Tamil Nadu, India
Abstract
Response of Trichoderma harzianum to different nickel concentrations was investigated by poison food technique. It was noticed that T. harzianum was moderately tolerant up to 60 mg/L, where the inhibition of mycelial growth was 33.3 %. Further increase in Ni concentration decreased the growth and total inhibition was observed at 200 mg/L. The chromium (VI) biosorption ability of Trichoderma harzianum was tested in-vitro. The organism was inoculated on Czapek Dox broth medium containing 50 mg/L of Ni salt. The metal residues were analyzed at different day’s interval (4, 5, 6, 7 and 8 days). The effect of different pH and temperature on metal removal was also investigated. Results indicated that, at 7th day the metal removal reached the maximum level (90.2 %). Further incubation did not increase the metal uptake. A pH range of 4-5 and temperature of 30 °C was optimum for Ni uptake by T. harzianum in the present study.

Research Article | Published online : 12-Apr-2010

Research Journal of Agricultural Sciences
Vol : 1 - Issue : 2 ; 75-79
Mushtaq A. Wani*, Shaista Nazir, S. A. Bangroo, M. A. Malik and P. Singh*
*Directorate of Research, Division of Soil Science, S. K. University of Agricultural Sciences and Technology of Kashmir, Shalimar, Srinagar-191 121, India
Abstract
The release of NEK from three soils of different physiographic region of Kashmir Valley was investigated using the Q-1 relationship of potassium. A plot of change in each K (±ΔK) against activity ratio of K, aK/a (Ca+Mg)1/2, gave a linear relationship in all the soils with a curved part at low K activity ratio. The value of labile-K (K1) obtained as intercept of Q/I plot on Y-axis ranged from 0.25 to 0.6 cmol kg-1. Total removal of K in maize, brown sarson and oat was closely related to the activity ratio of K measured at graded levels of K application. The relationship between the activity ratio of K and the amount of K (Kee) obtained after subtracting K uptake (Kup) by crop plants from the sum total of K present on nonspecific sites and adding or subtracting the amount by which exchangeable K increased or decreased, respectively. On equilibrium with different K-levels, (±ΔK) gave a negative intercept on quantity axis. This suggests the release of initially non liable K into the labile pool during plant growth. There had been no such release; the plot would have passed through the origin. The value of negative intercept gave a measure of the amount of NEK released. This value was 0.94 cmolkg-1 (733.2kgha-1) for Kokarnag soil, 0.62 cmol Kg-1 (483.6kg ha-1) for Kreeri soil and 0.70 cmol kg-1(546.0 kg ha-1) for Mazhama soils each cropped with maize, brown sarson and oat.

Research Article | Published online : 12-Apr-2010

Research Journal of Agricultural Sciences
Vol : 1 - Issue : 2 ; 80-84
Asima Amin, Yogesh Vikal*, T. S. Dhillon and Kuldeep Singh*
Department of Vegetable Crops, *School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana-141 004, Punjab, India
Abstract
Genetic variability is the pre-requisite for genetic improvement of a crop. Thirteen morphological markers, four biochemical markers and twenty RAPD primers were employed to estimate genetic diversity and to characterize 48 carrot genotypes possessing special attributes. The analysis based on morphological or field observations, biochemical constituents and RAPD primers revealed wide genetic diversity in the germplasm evaluated. The RAPD primers generated 254 bands of which all (100%) were polymorphic. The polymorphic information content (PIC) for the 20 primers ranged from 0.83 in Oligo-679 to 0.94 in OPS-13. The similarity coefficient analysis revealed five clusters. These clusters were further classified in sub- clusters. Cluster I has 4 sub-clusters, cluster II has 2, cluster III has 3 and cluster IV has 1 sub-cluster. The RAPD analysis proved helpful for estimating the magnitude of genetic diversity and for establishing genetic relatedness among germplasm.

Research Article | Published online : 13-Apr-2010