Browsing by Author "Jiji George"

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    Assessment of cross-taxa utility of coconut microsatellite markers
    (2008-09) Anitha, N.; Lakshmi Jayaraj, K.; Arun Kumar, E.P.; Jiji George; Rajesh, M.K.
    Micro-satellite or simple sequence repeats (SSRs) are abundant across eukaryotic genomes and show high levels of polymorphism. Micro-satellite DNA often has flanking regions that are highly conserved in related species and this renders the primer pairs designed in one species useful for the amplification of the same DNA region in related genomes, minimizing laborious cloning and screening steps. The present investigation explored the transferability of coconut SSRs to other palms, viz., oil palm, arecanut, palmyrah and date palm. The annealing temperature of 86 coconut-specific SSR primers was standardized using gradient PCR. Of the 86 primers, 55 primers gave clear bands of expected size range (100 to 300 bp) and these were tested for their cross-taxa amplification. The percentage of cross-amplification of coconut SSR loci were 36.36% in oil palm, 29.09% in arecanut, 18.18% in palmyrah and 12.70% in date palm. The results suggest usefulness of coconut SSRs for phylogenetic and comparative genomic studies in other palms.
  • Thumbnail Image
    Item
    Assessment of genetic fidelity of arecanut plantlets derived through direct somatic embryogenesis by RAPD markers
    (Indian Society for Plantation Crops, 2008) Anitha Karun; Radha, E.; Sangeetha Vijayan, P.; Jiji George; Rajesh, M.K.; Ananda, K.S.
  • No Thumbnail Available
    Item
    Evaluation of molecular diversity of ex situ conserved germplasm of palmyrah (Borassus flabellifer L.) accessions using RAPD markers
    (2016-08) Jiji George; Venkataraman, K.T.; Nainar, P.; Rajesh, M.K.; Anitha Karun
    The genetic relationship of 96 palmyrah palms, consisting of 24 indigenous accessions from Tamil Nadu and Andhra Pradesh, was investigated using Random Amplified Polymorphic DNA (RAPD) markers. Hundred and eighty primers were used initially to identify the polymorphic primers in six random samples and 10 polymorphic primers were selected to amplify the 96 palms. These 10 primers produced a total of 112 reproducible bands and out of them, 41 fragments (36.6 %) showed polymorphism. The number of bands produced with each primer varied from seven to 15 with an average of 11.2 bands per primer. The percent polymorphism ranged from 7.7 to 71.4 with an average of 37.4 per cent when all the primers were taken collectively. UPGMA grouped all the accessions into two major clusters at 0.85 similarity value. The highest similarity value (0.96) was observed between the accessions KLKM-8 and THY-54 and the lowest similarity value (0.782) was obtained between ANBI-17 and RCML-11. The relatively low polymorphism suggests a narrow genetic diversity of palmyrah populations from which the present accessions have been derived and maintained over the years.
  • Thumbnail Image
    Item
    Existence of co-sexuality in palmyrah palm and study of relationship between monoecious and dioecious palms using molecular markers
    (Indian Society for Plantation Crops, 2008) Jiji George; Venkataramana, K.T.; Anitha Karun; Rajesh, M.K.
  • Thumbnail Image
    Item
    Genetic diversity in yellow dwarf populations of coconut assessed using RAPD markers
    (2008-03) Ritto Paul; Jiji George; Rajesh, M.K.; Augustine Jerard, B.; Niral, V.
  • Thumbnail Image
    Item
    Identification of RAPD markers linked to sex determination in palmyrah (Borassus flabellifer L.)
    (2007-10) Jiji George; Anitha Karun; Manimekalai, R.; Rajesh, M.K.; Remya, P.
  • Thumbnail Image
    Item
    Marker assisted detection of seed sex ratio in palmyrah palm (Borassus flabellifer L.)
    (2011) Jiji George; Anitha Karun
    The palmyrah palms are slow-growing dioecious perennials and have no distinguishing features to identify the sex until flowering. The palm commences flowering only after 12–15 years of maturity. The seed sex ratio (primary sex ratio) was estimated by germinating seeds and growing seedlings under favourable conditions with minimal mortality until flowering. Early sex determination was done to assess the seed sex ratio of one-, two- and three-seeded fruits with a male-specific random amplified polymorphic DNA marker. The seed sex ratio (M : F) of seedlings raised from one-, two- and three-seeded fruits were 57 : 43, 35 : 65 and 61 : 39 respectively. There was no correlation between the number of seeds in a fruit and sex of the seedlings raised from them. The overall percentage of M : F was 52 : 48, which was almost 1 : 1 ratio. While comparing the sex ratio of one-, two- and three-seeded fruits individually, the sex-ratio of two-seeded fruits was 0.350 with probability 0.263. This indicated a female-biased sex ratio (M : F) in two-seeded fruits (35 : 65).