Influence of Foliar Sprays of Thiourea and Sulfuric Acid against Frost Injury in Berseem

Berseem (Trifolium alexandrinum L.) is an important winter season fodder crop which occupies 2 million ha area in India (Kumar et al., 2013). Berseem is generally grown as pure stands or in mixture with annual grass species for feeding to the livestock. During severe winter month periods from December to February, berseem growth is slow due to low minimum air temperature or cold wave or frost occurrence which affects fodder availability to the livestock. To increase growth of berseem either in pure stand or in mixture, farmers generally use excessive urea which not only affects nodule development in roots of legumes but also pollute the environment (Dogra and Dudeja, 1993). Mixture of berseem clover with cereal crop enhances total dry matter yield, improves fodder quality, reduces fertilizer use and also increases subsequent crop yield (Ross et al., 2004). Farmer harvests 3-4 cuttings of berseem up to late mid April as fodder for livestock and then leave the crop for seed production. After 3-4 cuts as green fodder, berseem plants retain less foliage, poor flowering and finally low seed production (Kumar et al., 2013). It is very essential that berseem crop attains sufficient height and tillering capacity during initial cuts for obtaining high fodder yield during slow growth and later on crop left for seed production produces good quantity and quality of seed. So, keeping this objective in view, a field experiment was designed to know the effect of different chemical foliar sprays during early cuts on the growth of berseem grown as pure stand and in mixture against very low minimum air temperature/frost injury

Effect of stem reserve mobilization on grain filling under drought stress conditions in recombinant inbred population of wheat

Pre-anthesis carbon assimilation of stem reserves is considered as an important source for grain filling during post anthesis drought stresses that inhibit photosynthesis. 175 RILs from cross (C518/2*PBW343) along with check cultivars were evaluated for stem reserve mobilization under irrigated and rainfed conditions. These two cultivars belonging to distinct adaptation mechanism, offer several morpho -physiological and biochemical con-trasts. C 518 is tall and adapted to low input rainfed conditions whereas PBW 343 is semi -dwarf and input re-sponsive. Further C 518 is known for better stem reserves on account of larger peduncle and strong commitment to grain filling due to effective stem reserve mobilization. The parents and the RIL population was tested for stem reserve mobilization by defoliation of flag leaf and second leaf at anthesis under irrigated and rainfed environments. Evaluated entries differed significantly (p<0.001) for reduction in 1000 grain weight under defoliation (TGWL). Percent reduction in 1000 grain weight ranged from 4.4 % to 39.6 % under irrigated environment and 3.2 % to 35.0 under rainfed condition. A significant positive correlation (r = +0.357) between stem reserve mobilization and peduncle length was observed under rainfed condition. Tested RILs vary individually for stem reserve mobilization when subjected to removal of flag leaf and second leaf inhibiting the photosynthesis. The genotypes with better stem reserve mobilization based on 1000 grain weight in the absence of photosynthesis may also provide relative tolerance to drought

BIPLOT ANALYSIS FOR IDENTIFICATION OF SUPERIOR GENOTYPES IN A RECOMBINANT INBRED POPULATION OF WHEAT UNDER RAINFED CONDITIONS

Physiological traits of wheat genotypes and their trait relation to drought conditions are important to identify the genotype in target environments. Thus, genotype selection should be based on multiple physiological traits in variable environments within the target region. This study was conducted at Punjab Agricultural University during rabi crop seasons 2012-13 and 2013-14 to study the recombinant inbred lines (RILs) of wheat genotypes derived from traditional landraces and modern cultivars (C518/2*PBW343) based on various morpho-physiological traits. A total of 175 RILs were selected for this study based on various tolerance indices. The genotype by trait (GT) biplot analysis was applied to data from seven high-yielding RILs grown under irrigated (E1) and rainfed environments (E2). The GGE biplot explained 100% of the total variation for chlorophyll content, grain filling period, peduncle length, water-soluble carbohydrates, grain number, grain yield, and 95.1% for canopy temperature, 94.9% for thousand-grain weight. GT-biplots indicated that the relationships among the studied traits were not consistent across environments, but they facilitated visual genotype comparisons and selection in each environment. RIL 84 and RIL108 were close to the average environment (ideal genotype) for all traits studied except chlorophyll content. A well-performing genotype with great environmental stability is called an "ideal genotype. Among all entries, these genotypes performed well. Therefore, among the traits studied, grain filling period, peduncle length, canopy temperature, water soluble carbohydrates, and 1000 grain weight contributed to grain yield under a stress environment. Furthermore, it may be used as a donor material in breeding programs and QTLs mapping

Seed priming effects on germination, growth and yield of dry direct-seeded rice

Insufficient seedling stand establishment is one of the major obstacles for achieving potential yield of dry direct-seeded rice (Oryza sativa L.). In the present study, seed priming technique was explored for improving germination and crop performance of dry direct-seeded rice. Seed-priming treatments used during the investigation included untreated control, hydro-priming, water hardening, and osmo-hardening with KCl. Priming reduced mean germination time and improved germination index, seedling vigor index, and germination energy. Hydro-priming was the best treatment, followed by water hardening, in improving seedling growth, leaf area index, panicles/m , and grain yield of dry direct-seeded rice

Effect of stem reserve mobilization on grain filling under drought stress conditions in recombinant inbred population of wheat

Pre-anthesis carbon assimilation of stem reserves is considered as an important source for grain filling during post anthesis drought stresses that inhibit photosynthesis. 175 RILs from cross (C518/2*PBW343) along with check cultivars were evaluated for stem reserve mobilization under irrigated and rainfed conditions. These two cultivars belonging to distinct adaptation mechanism, offer several morpho -physiological and biochemical con-trasts. C 518 is tall and adapted to low input rainfed conditions whereas PBW 343 is semi -dwarf and input re-sponsive. Further C 518 is known for better stem reserves on account of larger peduncle and strong commitment to grain filling due to effective stem reserve mobilization. The parents and the RIL population was tested for stem reserve mobilization by defoliation of flag leaf and second leaf at anthesis under irrigated and rainfed environments. Evaluated entries differed significantly (p<0.001) for reduction in 1000 grain weight under defoliation (TGWL). Percent reduction in 1000 grain weight ranged from 4.4 % to 39.6 % under irrigated environment and 3.2 % to 35.0 under rainfed condition. A significant positive correlation (r = +0.357) between stem reserve mobilization and peduncle length was observed under rainfed condition. Tested RILs vary individually for stem reserve mobilization when subjected to removal of flag leaf and second leaf inhibiting the photosynthesis. The genotypes with better stem reserve mobilization based on 1000 grain weight in the absence of photosynthesis may also provide relative tolerance to drought

Uncovering the Iranian wheat landraces for salinity stress tolerance at early stages of plant growth

Soil salinity is a major global environmental factor limiting plant growth and productivity. Wheat seeds need to be able to germinate and establish seedlings in saline soils for sustained productivity. In this study, we investigated seed germination-related traits under salt stress conditions in 239 diverse Iranian wheat landraces for evaluation of salt stress tolerance. Seed of the landraces along with relevant checks was germinated in salt and control solutions until 14 days. Initially, 10 randomly selected accessions were subjected to six different (25 mM, 50 mM, 75 mM, 100 mM, 125 mM, 150 mM) salinity levels for standardization. The salinity level 125 mM NaCl was found more effective concentration for the discrimination of genotypes for various physiological indices, viz. germination percentage, coleoptile length, root and shoot length, fresh root and shoot weight, dry root and shoot weight, and vigor index. After 14 days, germination percentage and all seedling traits were found to be affected due to salinity. Salt tolerance index maintained a significant positive correlation with seedling traits which indicates that these parameters could be used as selection criteria for screening wheat genotypes against salt stress. Significant differences were observed for coleoptile length, root–shoot length, fresh root–a shoot weight, dry shoot weight, and vigor index among the wheat landraces. From the overall observation of germination percentage and early seedling growth, it was concluded that the wheat landraces accessions including IWA 8600278, IWA 8600291, IWA 8611786, IWA 8600179, IWA 8600303, and IWA 8610487 showed better salt tolerance than Kharchia 65, the universal salt-tolerant variety used so far in wheat-breeding programs

Session 08 Germination and dormancy

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