No abstract

The most taxonomically perplexing type of plant group is the polyploid complex (Stebbins 1938). In such a complex species have mostly common morphological features besides the closely similar genomes. This provides a good source for the study of interrelationships and origin of species. Solanum nigrum is a good example of polyploid complex based on X=12 chromosomes.A good deal of work has already been done to find out the relationships among the species of S. nigrum complex (Chennaveeraiah and Patil 1968, D'Arcy 1974, Edmonds 1977, Khan et al. 1977, 1978, 1985, Schilling and Heiser 1979, Rao and Kumar 1984, Ganpathi and Rao 1986 but still the clear picture of the interrelationships among the several members of this complex is to come out. Therefore, the cytogenetical investigation has been carried out to find out the interrelationship between S. opacum and Sm furcatum of S . nigrum complex. Materials and methodsThe seeds of Solanum opacum were obtained from Dr. J. M. Edmonds, Cu. Botany School, University of Cambridge, England and the seeds of Solanum furcatum were obtained from the collection maintained by the Department of Botany, A. M. U., Aligarh.Reciprocal cross pollinations were made between these two species. For meiotic studies, fl ower buds were fixed in Carnoy's fluid for 20 minutes, then kept for 24 hours in propionic alcohol (1:3), saturated with ferric acetate powder and finally stored in 70 per cent alcohol. Meiosis was studied by simple propionocarmine squashes of pollen mother cells (Swaminathan et al. 1954). The temporary slides were made permanent by butyl alcohol schedule (Bhaduri and Ghosh 1954). The pollen fertility was determined by observing the number of pollen grains stained with 1 per cent acetocarmine. Those pollen grains which took stain and had regular outline were taken as fertile pollens and empty, unstained or poorly stained ones were taken as sterile. The size of pollen grains was estimated by measuring its diameter with the help of ocular micro-meter scale and the ocular divisions were converted into microns for determing the size of pollen grains. The pollen grains were collected from five different samples. ObservationsA statistical comparison of the morphological characters of the two species showed con sistant differences with respect to several characters such as habit of plants, colour of berry and size of leaf ( Fig. 1 and Table 1).Fifty cross pollinations were made between S. furcatum and S. opacum using S. furcatum as pistillate parent. Out of these only 18 mature fruits with a total number of 63 seeds were obtained.All the seeds were sown but the germination was only 31.74 per cent. Fifty re ciprocal crosses were made which gave 20 mature fruits with 80 seeds. The percentage of germination was 32.50. The hybrids of reciprocal crosses were morphologically similar. A

No abstract

No abstract

Barcoding of Cycas pschannae Srivast. & Singh from Andaman & Nicobar Islands was done with the help of rbcL and ITS(Standard Universal Barcode Sequence- CBoL) and submitted to GenBank. Phylogenetic relationship of this species was analyzed and Cladistic study of nine Cycas species from India and adjacent country including Cycas revoluta thunb had been conducted with help of BLAST tool by using rbcL barcode sequence, which reveals that Cycas pschannae has close relation with Cycas circinalis as compared to other Indian species.