Molecular phylogeny of Heritiera Ait on (Sterculiaceae), a tree mangrove: variations in RAPD markers and nuclear DNA content

Random amplified polymorphic DNA (RAPD) markers are used to estimate interspecific variation among mangrove and non-mangrove Heritiera fomes, H. littoralis and H. macrophylla. All the species have 2n = 38 chromosomes, with minute structural changes distinguishing the karyotype of each species. Significant variation of 4C DNA content occurs at the interspecific level. Interspecific polymorphism ranged from 14.09% between H. fomes and H. littoralis to 52.73% between H. fomes and H. macrophylla. H. macrophylla showed wide polymorphism in the RAPD marker with H. littoralis (51.23%) and H. fomes (52.73%). Two distinct RAPD products obtained from OPA-10 (1000 bp) and OPD-15 (900 bp) found characteristic molecular markers in H. macrophylla , a species from a non-mangrove habitat. H. macrophylla was more distantly related to H. fomes [genetic distance (1-F) = 0.305] than to H. littoralis [genetic distance (1-F) = 0.273]. H. littoralis was of a closer affinity to H. fomes [genetic distance (1-F) = 0.218] than to H. macrophylla.     

Geographic variation in jungle cat (Felis chaus Schreber, 1777) (Mammalia,Carnivora, Felidae) body size: is competition responsible?

There is a striking difference in body size of jungle cats ( Felis chaus ) in the west and the east of their distribution, with Israeli cats being 43% heavier than Indian cats. We tested the hypothesis that increasing competition from other small felids towards the east is responsible for the difference in body size. We measured jungle cat skulls for eight cranial and dental variables and related these to independent variables such as species richness (local and regional), latitude, longitude, temperature, and precipitation. Data from a narrow band between latitudes 24.0°N and 33.9°N, where Bergmann's rule was largely not observed, showed that the western population (≤ 50.0°E longitude) of jungle cats is larger than the eastern (> 60.0°E longitude) population with the size difference being most evident in the upper carnassials (P⁴L). Species richness at the regional level showed a significant negative relation to P⁴L. An even spacing in condylobasal length for a small-cat guild from India through null model analysis indicated the occurrence of character displacement. The results support the hypothesis that competition is responsible for geographical variation in jungle cat body size in the region where Bergmann's rule does not apply. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 92 , 163–172.     

Shelf-life enhancement of fresh ginger rhizomes at ambient temperatures by combination of gamma-irradiation, biocontrol and closed polyethylene bag storage

The feasibility of a combination process involving gamma-irradiation, packing in closed polyethylene bags and biological control of fungi causing storage rot was evaluated as a means of extending the shelf-life of fresh ginger rhizomes at ambient temperatures (25–30°C). Storage in closed polyethylene bags reduced weight loss but increased sprouting and rooting, which could be prevented by gamma irradiation to 60 Gy. Rotting caused by Sclerotium rolfsii was, however, a major cause of spoilage during extended storage.
Four isolates of Trichoderma sp. isolated from sclerotia of S. rolfsii infecting ginger rhizomes, one of Gliocfadium uirens, and four isolates of fluorescent Pseudomonas were tested, out of which, one isolate of Trichoderma was found to be highly effective in suppressing the growth of S. rolfsii. The efficacy of the antagonist was demonstrated under simulated market conditions using artificially inoculated rhizomes. The recommended procedure consists of dipping washed, air dried rhizomes in Trichoderma suspension (10⁸spores ml^-1), air-drying, packing in 250 gauge LDPE bags followed by irradiation to 60 Gy. Rhizomes thus treated remained in good marketable condition for up to 2 months at ambient temperature without sprouting or significant loss of quality and less than 5% weight loss.
An in vitro bioassay system was developed to demonstrate the efficacy of the antagonist to protect the cut surface of sliced rhizomes inoculated with the pathogen. The method could be used for rapid screening of antagonists.     

Morphological and Biochemical Investigations on Ipomoea Seedlings and their Species Interrelationships

Studies on seedling morphology and the isozyme profile of 12species ofIpomoea , undertaken with a view to tracing the linkageand homology between the species, revealed the concordance ofmorphological findings with biochemical analysis. The trendof clustering in the dendrogram based on isozyme profiles revealedtwo broad clusters or groups. Interrelationships and homologybetween the species revealed by the phyletic tree constructedfrom seedling morphology and from the dendrogram on isozymedata were comparable, with only minor variations. Ipomoea spp.; seedlings; morphology; isozymes; dendrogram; phyletic tree