Construction of intersubspecific molecular genetic map of lentil based on ISSR, RAPD and SSR markers

Lentil (Lens culinaris ssp. culinaris), is a self-pollinating diploid (2n?=?2x?=?14), cool-season legume crop and is consumed worldwide as a rich source of protein (~24.0%), largely in vegetarian diets. Here we report development of a genetic linkage map of Lens using 114 F₂ plants derived from the intersubspecific cross between L 830 and ILWL 77. RAPD (random amplified polymorphic DNA) primers revealed more polymorphism than ISSR (intersimple sequence repeat) and SSR (simple sequence repeat) markers. The highest proportion (30.72%) of segregation distortion was observed in RAPD markers. Of the 235 markers (34 SSR, 9 ISSR and 192 RAPD) used in the mapping study, 199 (28 SSRs, 9 ISSRs and 162 RAPDs) were mapped into 11 linkage groups (LGs), varying between 17.3 and 433.8 cM and covering 3843.4 cM, with an average marker spacing of 19.3 cM. Linkage analysis revealed nine major groups with 15 or more markers each and two small LGs with two markers each, and 36 unlinked markers. The study reported assigning of 11 new SSRs on the linkage map. Of the 66 markers with aberrant segregation, 14 were unlinked and the remaining 52 were mapped. ISSR and RAPD markers were found to be useful in map construction and saturation. The current map represents maximum coverage of lentil genome and could be used for identification of QTL regions linked to agronomic traits, and for marker-assisted selection in lentil.     

Sucrose metabolism in Sorghum vulgare at ripening

Enzymes associated with sucrose metabolism in root, stem, leaf and grain of Sorghum vulgare Pers. (cv. JS 263) were studied at the ripening stage. Sucrose phosphate synthetase was dominating in the leaf and sucrose synthetase in the grain. Invertases were more active in leaf, root and stem tissues than in grains. The maximum activities of ADPG pyrophosphorylase and UDPG pyrophosphorylase were found in grains and leaves, respectively. Sucrose synthetase from grains catalyses both synthesis and cleavage of sucrose but the two activities differed in their responses to the effect of temperature, pH and type of buffer. The Km values of the enzyme for UDPG, ADPG, GDPG, TDPG and CDPG were 8.5, 5.3, 16.8 2.2 and 10.7 mM, and for UDP and ADP they were 17.2 and 55.0 mM respectively.     

Polar Lipids of Spinach (Spinacia oleracea) Roots

The polar lipid components in the roots of spinach (Spinacia oleracea) plant were identified as phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine, monogalactosyl-diglycerides, digalactosyldiglycerides, polygalactosyldiglycerides, sulpholipids and three unknown glycosides. Phospholipids constituted only 10% of the polar lipid fraction and 90% was of nonphosphatidic nature. This latter fraction was highly unsaturated and contained linoleic acid as the major fatty acid component.     

Lipids in Berseem Seed (Trifolium alexandrinum) during Germination as Affected by Gibberellic Acid and Maleic Hydrazide

Lipid depletion of berseem seed treated with 100 mg/1 gibberellic acid or maleic hydrazide was studied during germination. During the first 3 days after germination there was little lipid consumption but thereafter the depletion of lipid was rapid. Gibberellic acid was found to enhance the lipid utilization of total lipids and triglyceride components during germination. On the other hand, maleic hydrazide reduced the utilization of triglycerides of the germinating seed. The rate of utilization was rapid for unsaturated fatty acids and slower for saturated ones in treated seeds as compared to untreated seeds.     

Fatty Acid Synthesis in Hydrilla Chloroplasts

The rates of carboxylation, photophosphorylation and acetate incorporation have been compared in the intact and broken chloroplasts of Hydrilla verticillata Royle leaves in the presence and absence of certain inhibitors and metabolites. The intact chloroplasts showed low rates of photophosphorylation, high rates of carboxylation, and exhibited normal capacity for fatty acid biosynthesis. In broken chloroplasts a drastic decrease was observed in the rates of carboxylation and acetate incorporation. However, the rate of photophosphorylation was considerably increased. In the presence of light, inhibitors such as iodoacetamide, arsenite and sodium azide decreased the photophosphorylation rate. F-1,6-di-P and PGA stimulated CO₂ fixation rate. In the absence of artificial light, inhibitors such as sodium arsenite, gluconate-6-phosphate, sodium azide and iodoacetamide decreased the rate of CO₂ fixation. CoA, ATP, G-6-P, F-1,6-di-P Stimulated the synthesis of fatty acids. Exogenous supply of ADP. NADH, NADP and NADPH did not stimulate fatty acid biosynthesis probably because these compounds could not gain entry into the chloroplasts. Light was necessary for the in vitro fatty acid biosynthesis.