No abstract

A study was conducted on a 15×15 diallel set of tomato excluding reciprocals to find out the extent of heterosis, combining ability and nature of gene action for yield with two important quality traits: ascorbic acid (vitamin C) and total soluble solids (TSS). Significant differences among genotypes were obtained for all three traits. Positive high significant heterosis was found for yield (41·97, 157·84 and 28·94%), for ascorbic acid (16·68, 54·57 and 161·33%) and for TSS (25·97, 11·93 and 19·02) over the top, the better parent and the commercial control respectively. The magnitude of variance due to general as well as specific combining ability were highly significant indicating the importance of both additive and non-additive gene action. However degree of dominance (o−2 g/o−2 s) revealed the prevalence of a non-additive gene effect. Cross combinations Arka Vikas×Sel-12 (13·19), KS-10×Pant T-3 (1·66) and EC 818703×EC 13042 (0·88) were best specific combiners for ascorbic acid, total soluble solids and yield/plant. Predominance of non-additive gene action plays a greater role in the inheritance of ascorbic acid and total soluble solids in tomato under hill conditions.

Five new species of the genus Oxyopes (Araneae: Oxyopidae), 0. elongatus n. sp., 0. minutus n. sp., 0. ovatus n. sp., 0. reticulatus n. sp. and 0. subimali n. sp. are recorded from Buxa Tiger Reserve, West Bengal, India. A total of 9 Oxyopes species are reported from the area.

Spiders are one of the important predatory arthropods that comprise the largest order Araneae of the class Arachnida. In Bangladesh, very few contributions are available on the taxonomic study on these arachnids. The present paper contains an updated checklist of the spider fauna of Bangladesh based on the published records of different workers and the identified collections of the recent studies by the author. It includes a total of 334 species of spiders belong to the infraorders Mygalomorphae and Araneomorphae under 21 families and 100 genera. A brief diagnosis of different families and their domination together with the distribution throughout the country are provided herewith.

Four species, Heteropoda acuta n. sp., Hippasa part ita, Pardosa duplicata n, sp. and P. sumatrana are for the first time known to be the members of the spider fauna of Buxa Tiger Reserve.Hippasa partita is a new record from India. All these four species are reported or described.