Asymmetric development of Cotyledons of Tomato Embryo: Testing the prediction of Self-Organization

Developmental biologists have long strived to understand how organisms acquire shape and form. The architecture of the mature plant is established during embryogenesis. They have learned much about how gene expression controls the specification of cell type and about how cells interact with one another to coordinate such specific decisions. Far less is known about autocatalytic feedback flow of resource molecules regulating a plant and its parts, shape and form. Indeed, it has even been proposed that the development of shape is not under genetic control but rather is determined by physical forces. Asymmetric development of sinks that depend on common resource pool has been viewed as a consequence of autocatalytic feedback process of flow of resource units into them. The feedback process implies that the stronger a sink is relative to its competitors, the greater is its probability of getting further resources as a non-linear function of its resource drawing ability and sink size. We have shown that this model contrasts with that of sink strength dependent model in its prediction of the subsequent development of the initial asymmetry of growing cotyledons of the tomato embryo (_Lycopersicon esculentum L._), when their resource drawing ability is enhanced by exogenous application of the growth regulators (NAA, GA and BA), we test these prediction and show that the results are in conformity with the autocatalytic model proposed by Ganeshaiah and Uma Shaanker

Assessing the Genotypic Differences for Seed Set and Seed Abortion in Tomato Genotypes

Tomato (_Lycopersicon esculentum_ Mill.) is one of the most popular fruit vegetable around the world. Seed abortion where in only a small proportion of ovules in an ovary develops into matured seeds, is a wide spread phenomenon in multi-ovulated species. In agriculturally important crops such as chickpea, groundnut, Brassica, pigeon pea and field bean seed abortion substantially reduces their productivity. Tomato genotypes exhibited seed abortion where in only some proportion of ovules developed into matured seeds. Seed abortion in tomato cultivars would increase the cost of hybrid seed production. In this study, we have analyzed 19 genotypes for number of ovules, seed set and seed abortion. Tomato genotypes differed significantly for number of ovules per ovary, seed set per fruit and per cent seed abortion. The ovules, matured seeds and seed abortion ranged from 52 to 412 per ovary; 50.90 to 240.76 per fruit and 6.06 to 24.44 per cent respectively. Strong positive correlation was observed in genotypes with higher number of ovules showed higher percentage of seed abortion

Enhancing Jatropha Productivity by Canopy Management

Jatropha seed and oil yield is function of planting material used, growing conditions, plant architecture development and maintenance. Jatropha is hardy plant; thrives well in arid and semi arid regions with an average rainfall ranging from 500 to 1200 mm. It has been planted in varied soil types, marginal and waste lands; where in utilization of in situ resources by agronomic practices and development and management of canopy by pruning are very crucial for harvesting higher seed for biodiesel production. Building ideal canopy by pruning during first growing season is very important. Pruning is done during winter season when plants are in dormant condition

Photoacoustic spectroscopy of sprayed CuGaxIn1−xSe2 thin films

CuGaxIn1−xSe2 thin films have been produced using spray-pyrolysis. The layers were deposited onto Mo-coated soda-lime glass at a substrate temperature of 623 K, and the gallium content of the layers varied. The layers were investigated using photoacoustic spectroscopy. The normalised photoacoustic spectra of CuGaxIn1−xSe2 films with x=0, 0.2, 0.4 and 0.5 showed a sudden fall in the photoacoustic signal at photon energies of 0.99, 1.15, 1.27 and 1.36 eV, respectively, which correspond to the respective direct energy band gaps of these films. The photoacoustic spectra also showed peaks at 0.75, 0.78, 0.82, 0.86 and 0.88 eV, respectively, in the sub-band gap region, which have been attributed to the defect states within these films

A New Jatropha curcas Variety (JO S2) with Improved Seed Productivity

One key reason for the failure of Jatropha plantation is the use of non-improved planting materials. We present in this paper a Jatropha variety (JO S2) through selective breeding with much better seed productivity than wild accessions as proven by field trials in Singapore and India. In a single farm trial in Singapore for two years, a comparison was conducted with accessions from China, India, Indonesia and Africa. It was found that all traits studied like seed yield, seed kernel content, seed oil content, fatty acid composition, phosphorus content and PE content differed significantly among and within the wild accessions. Overall, JO S2 was the best performer with the highest seed yield, high oil content and low phosphorus content. On two sites in Tamil Nadu, Southern India, this Jatropha variety produced up to 2.95 ton/ha of dry seeds in the first year and up to 4.25 ton/ha of dry seeds in the second year, much better than the local variety control. We attribute its higher seed productivity to early flowering, better self-branching, more flower/fruiting bunches, more fruits per bunch and importantly, better uniformity among plants. This exemplifies that breeding has improved Jatropha seed productivity which will lead to better economics for Jatropha plantation