Diversity in germination of seeds inCalotropis procera R.Br. population

Summary Phenotypically there appeared to exist no diversity in different individual plants in a population ofCalotropis procera. The diversity in imbibition and germination behaviour of seeds from different plants was revealed only after detailed studies were undertaken. Seeds from six individual plants were collected and stored separately for a period of two years. Ordinarily the seeds of this species did not exhibit any dormancy and were found to germinate immediately after harvest. Two years old seeds did not loose their viability in any of the six lots indicated above. It was discovered that the weight and size of seeds, the rate of imbibition of water, the amount of water imbibed, the loss of water upon drying, the rate of germination, the percentage of germination, and the germination behaviour in continuous illumination and total darkness, all exhibited diversity to some extent in the six lots studied. It was evident that there did not exist seeds exhibiting homogeneous behaviour in a population ofCalotropis procera.     

Edgeworthin,a new bis-coumarin from Edgeworthia gardneri

Besides daphnoretin and edgeworthin, a new bis-coumarin, was isolated from the stem-bark of Edgeworthia gardneri. Spectral and chemical evidence led to a structure in which two coumarin units are linked by an oxygen bridge between carbons 3 and 7′.     

Biotypic differences in the karyology ofPennisetum pedicellatum Trin

Detailed karyological analyses have been made of the five biotypes ofPennisetum pedicellatum Trin. These biotypes not only differ in some morphological traits but also in their chromosomal characteristics. Biotype-B with 2n = 48 chromosomes shows constancy, while in the other four 2n = 36 and 64 are found to be “floating”. Other numerical variations include 2n = 42 and 18 chromosomes. Minute karyological differences are not only noted amongst the biotypes, but also there are variations in the complements within a biotype. Such variations are presumed to be buffered through the apomictic mode of reproduction. From the morphological and cytological studies, the possibility of separation of biotype-B from the complex in future has been envisaged.     

An Ethnography of Dementia

Culture, Medicine, and Psychiatry - The experiences of dementia sufferers have rarely been examined in sociological literature. This article seeks to describe the experiences of one Alzheimer's...     

Effect of sodium cyanide on germination of two leguminous seeds

Summary The effect of aqueous sodium cyanide has been studied on germination ofC. ternatea andR. minima seeds. The suitable concentration of this chemical accelerates imbibition, germination, and promotes the early growth of the seedlings. The best result is obtained by soaking the seeds for 24 hours in a solution of 100 ppm of sodium cyanide. As concentrations are increased the inhibitory effect becames more and more pronounced leading to the eventual suppression of normal germination and growth of the seeds. The mean germination time of the seeds, treated with effective and critical concentrations of the chemical, is decreased. Light and temperature conditions do not influence the chemical effect on the seeds.