Volume 72, Issue 6
December 1970, pages 241-294
pp 241-250 December 1970
The paper deals with the description of five species of digenetic trematodes, all collected from vertebrate hosts from Great Nicobar.
pp 251-260 December 1970
pp 261-265 December 1970
Utilization of raffinose as well as a mixture of its hydrolytic products (D-glucose, D-fructose and D-galactose, 1 : 1 : 1) byDrechslera australiense (Bugn.) Subram. and Jain andCurvularia tuberculata Jain isolated from diseased fruits (Lycopersicon esculentum Mill) and guava (Psidium guajava L.), respectively, was studied chromatographically. Both the organisms utilized raffinose through a hydrolytic pathway. The dry weights of both the organisms were superior on a mixture containing the hydrolytic products of raffinose than on raffinose alone. Glucose was used earlier by the organisms from the mixture of D-glucose, D-fructose and D-galactose.
pp 266-269 December 1970
Considerable uncertainty exists about the taxonomic status of the sciaenid genusBola Hamilton, 1822. The nomenclatural history of the genus is reviewed and its status discussed. This genus and its objective synonymWak Lin, 1938 are relegated to the synonymy ofJohnius Bloch, 1793.
pp 270-276 December 1970
Karyomorphological studies in a local population ofD. kirkii have revealed the somatic chromosome number of 2n=68. This is a new number and has made the cytological situation in the genus more complex in respect of the basic chromosome number. The chromosomes form a graded series with 4 pairs of satellited chromosomes. On the basis of the present observations a tetraploid level of a complex category has been suggested for this species. An analysis of meiotic stages and the chromosome number in the pollen grains is suggestive of the presence of 1–4 supernumerary chromosomes in the genome of the taxon.
pp 277-284 December 1970
Polyphenolase catalyses the hydroxylation of phenols and their oxidation to quinones, which are involved in different biological reactions. In the case of sandal the polyphenolase activity PPA) has been found to be distinctly at a higher level in the spiked leaves than in the healthy ones at all stages of development. This naturally accounts for the recorded higher level of phenolic bodies in the spiked sandal leaves.
Diseased sandal leaves show a higher rate of respiration. For this phenomenon, the higher level of quinones formed through the higher PPA appears to be partly responsible, since inhibition of the PPA using sodium diethyldithiocarbamate has definitely lowered the respiration rate. However, the residuary respiration is still higher than in the healthy tissues, thereby indicating that the PPA is only partly responsible for the increased respiration in the spiked leaves.
A higher level of phenols is known to affect adversely the indoleacetic acid oxidase activity in plant tissues and this appears to be the case in sandal also. The diseased tissues, which are shown to exhibit a higher level of PPA, contain more phenolic bodies which adversely affect the IAA oxidase activity, resulting in a higher level of IAA, particularly in the young leaves, and this factor appears to be responsible for the increase in the number of vegetative buds as is noticed in the spiked plants.
pp 285-287 December 1970
pp 288-294 December 1970
1. Karyotypes ofTherapon jarbua andT. puta have been studied from the gill epithelium after colchicine injections.
2. The diploid chromosome number in both the sexes of the two species is 48, all the elements being metacentrics.
3. The chromosomes measured from 1·76 to 4·0 µ inT. puta and from 1·76 to 3·4 µ inT. jarbua.
4. The karyotypes of the two species differ in two respects:—
The fourteenth pair inT. puta has submedian centromeres while inT. jarbua it has median centromeres.
There are 3 smaller pairs injarbua whereas only one pair is smaller inputa.
5. The inclusion of both the species under the same genusTherapon seems justified by the cytological findings.
6. It has been suggested from the available information that the families Serranidae and Sillaginidae may be closer to the family Theraponidae although this should await confirmation from further studies.
7. No heteromorphic pair or pairs of chromosomes have been observed in the karyotypes of either sex in both the species.