Not Available

Not AvailableThe translocation of 14C-sucrose to the different parts of the mustard (Brassica juncea) crop has been evaluated in the context of understanding the source to sink relationship in the thiol-induced enhanced crop yield. The foliar application of thiols like TU, TGA and DTT to the plant gave maximum sucrose phosphate synthase activity, which was found to have direct correlation with the movement of sucrose. The distribution pattern of 14C-sucrose follows the path from internode and node to pod via leaf. The translocation of 14C-sucrose was found to be a light dependent process. Among the nucleotides ATP and GTP, only ATP was able to promote the translocation and GTP was ineffective. In this unique in situ tracer experiment using 14C-sucrose, we could establish that thiols are able to enhance the translocation of sucrose from source to sink.Not Availabl

Not Available

Not AvailableRadioactively labeled iron (59Fe) was used to study differential uptake in sorghum plants in the recovery stage of chlorosis. Radio-labeled 59Fe was supplied through root feeding in nutrient solution experiment (48 hrs, pH 6.2) to non-chlorotic and chlorotic plants. Chlorotic plants were further treated with foliar spray [ferrous sulfate (FeSO4), FeSO4 + thiourea (TU), FeSO4 + citric acid (CA), FeSO4 + thioglycollic acid (TGA)] to study the uptake of radio-labeled 59Fe through root feeding during recovery process of chlorosis. Under iron deficiency, the differential uptake of 59Fe was markedly increased in leaves and stem of chlorotic control (-Fe) sorghum plants as compared to nonchlorotic control ( + Fe) and foliar sprayed (FeSO4, FeSO4 + TU, FeSO4 + CA, and FeSO4 + TGA) plants. The lowest uptake of 59Fe was observed in younger leaves (24.33 nmol, g−1 fresh weight h−1) and stem (1.98 nmol, g−1 fresh weight h−1) of non-chlorotic control followed by foliar sprayed plants in comparison to chlorotic control, respectively. Similarly less 59Fe uptake was observed in the older leaves of FeSO4 + CA sprayed (21.70 nmol, g−1 fresh weight h−1) plants in comparison to chlorotic control (35.60 nmol, g−1 fresh weight h−1). The highest differential 59Fe uptake through nutrient medium was in the roots of plants, which were foliar sprayed with FeSO4 along with TU. The role of iron alone and along with citric acid and thiol compounds is discussed in recovery of chlorosis.Not Availabl

Not Available

Not AvailablePhotosystem 1 and 2 and antioxidant enzyme activities were determined in wheat (Triticum aestivum L. cv. Sonalika) leaves. Seedlings from both control seeds and seeds soaked in solutions like dithiothreitol, thioglycollic acid and thiourea were subjected to water stress induced by polyethylene glycol. Photosystem 1 and 2 activities were less inhibited by water stress due to seed soaking with sulphydryl compounds. The changes in activities of antioxidant enzymes induced by water stress were higher in seedlings from thiol-pretreated seeds than from water-soaked seeds.Not Availabl

SSR analysis of the Medicago truncatula SARDI core collection reveals substantial diversity and unusual genotype dispersal throughout the Mediterranean basin

The world's oldest and largest Medicago truncatula collection is housed at the South Australian Research and Development Institute (SARDI). We used six simple sequence repeat (SSR) loci to analyse the genetic diversity and relationships between randomly selected individuals from 192 accessions in the core collection. M. truncatula is composed of three subspecies (ssp.): ssp. truncatula, ssp. longeaculeata, and ssp. tricycla. Analysis at the level of six SSR loci supports the concept of ssp. tricycla, all the samples of which showed unique alleles at two loci. Contingency Chi-squared tests were significant between ssp. tricycla and ssp. truncatula at four loci, suggesting a barrier to gene flow between these subspecies. In accessions defined as ssp. longeaculeata, no unique allelic distribution or diagnostic sizes were observed, suggesting this apparent ssp. is a morphological variant of ssp. truncatula. The data also suggest M. truncatula that exhibits unusually wide genotype dispersal throughout its native Mediterranean region, possibly due to animal and trade-related movements. Our results showed the collection to be highly diverse, exhibiting an average of 25 SSR alleles per locus, with over 90% of individuals showing discrete genotypes. The rich diversity of the SARDI collection provides an invaluable resource for studying natural allelic variation of M. truncatula. To efficiently exploit the variation in the SARDI collection, we have defined a subset of accessions (n = 61) that maximises the diversity