Trait phenotyping and SSR markers characterization of wheat (Triticum aestivum L.) germplasm for breeding early maturing wheat’s for Western-Himalayas

Genetic Resources and Crop Evolution - The study involved evaluation of 96 wheat genotypes for early maturity and related traits and molecular characterization of trait specific candidate genotypes...     

Radon Survey and Exposure Assessment in Karaca and ?al Caves, Turkey

Radon concentration and gamma activity concentration of naturally occurring radionuclides were determined and presented for two tourist caves (Karaca and Çal caves) in this study. These caves are reported to receive about 77,000 visitors during the summer season in 2007. It was seen that mean radon activity concentrations for the winter and summer seasons for the Karaca cave is 1,023 and 823 Bq/m³ and for the Çal cave is 264 and 473 Bq/m³. Mean ²²⁶Ra, ²³²Th, and ⁴⁰K activity concentrations are found to be 43, 19, and 262 Bq/kg for the Karaca cave and 31, 27, and 460 Bq/kg for the Çal cave. Doses received by the cave guides due to radon were estimated to be 2.9 mSv/year for the winter season and 2.3 mSv/year for the summer season for the Karaca cave. Same values were estimated for the Çal cave, and the results were found to be 0.6 mSv/year for the winter season and 1.1 mSv/year for the summer season. Annual effective doses received by the visitors in both caves were estimated to be in the order of ??Sv/year because of the short exposure time comparing the cave guides. Although the reported values are below the recommended values, both groups are exposed to possible radiological risk during their stay inside the cave, since prolonged exposure to high radon concentration has been linked to lung cancer.     

Variability of Soluble Salts Using Different Extraction Methods on Composts And Other Substrates

Soluble salts represent dissolved inorganic ions in solution and are typically measured in terms of electrical conductivity (EC). Often soluble salt measurements from different studies or laboratories cannot be cross-referenced or there is much confusion when comparing these results. The soluble salts from 13 composts and horticultural substrate materials were extracted using six different methods: saturated medium extract; pour-through, a water displacement method; and water suspensions using various ratios (by volume) of water:substrate (1:1, 1:2, 2;1, 5:1). EC ranged from 0.1 (peat and perlite) to 23.1 dS m^?1 (turkey litter compost). A linear regression model was developed to allow cross-referencing between extraction methods of measurements of soluble salts concentration of the composts and substrates.     

Denitrification and total fertilizer-N losses from an irrigated cotton field

 In a 2-year field study, denitrification loss was measured from an irrigated sandy-clay loam under cotton receiving urea-N at 158–173 kg ha^–1. An acetylene inhibition-soil core method was employed for the direct measurement of denitrification, considering also the N₂O entrapped in the soil. Taking into account the N₂O evolved from soil cores and that entrapped in the soil, a total of 65.7 kg N ha^–1 and 64.4 kg N ha^–1 was lost due to denitrification during the 1995 and 1996 cotton-growing seasons, respectively. Most (>70%) of the denitrification loss occurred during June–August, a period characterized by high soil temperatures and heavy monsoon rains. On average, 35% of the denitrification-N₂O was found entrapped in the soil and the amount of entrapped N₂O was significantly correlated with head space N₂O concentration and with water-filled pore space. ¹⁵N-balance during the 1996 growing season revealed a loss of 71.8 kg N ha^–1. It was concluded that a substantial proportion of the fertilizer-N applied to irrigated cotton is lost under the semiarid subtropical climatic conditions prevailing in the Central Punjab region of Pakistan and that denitrification is the major N loss process under irrigated cotton in this region. Received: 8 March 1999     

Association of isozyme markers with quantitative trait loci in random single seed descent derived lines of lentil (Lens culinaris Medik.)

Summary Polymorphism at isozyme loci was used to locate factors responsible for variation in quantitative traits of lentil. Eight sets of random single seed descent (RSSD) derived lines were developed by advancing individual F₃ plants of interspecific (L. culinaris Medik. × L. orientalis Boiss.) hybrids to the F₆. The RSSD lines in each of the eight sets differed for alleles at 2–8 isozyme loci. In each set, association of isozyme loci with variation in seven quantitative traits (days to flower, days to mature, plant height, biomass, seed yield, harvest index, seed weight) was determined for each pairwise combination of a quantitative trait with a marker locus. Loci affecting variation in all seven quantitative traits were detected by their association with 14 isozyme markers (Aat-c, Aat-m, Aat-p, Adh-1, Fk, Gal-1, Gal-2, Lap-1, Lap-2, Pgd-p, Pgi, Pgm-c, Pgm-p, Skdh). The known position of 10 the 14 isozyme loci on the lentil genetic map was used to mark the genomic regions for possible location of associated quantitative trait loci (QTL). Detected QTL were found to be located in six of the seven linkage groups on lentil genetic map. Regions of the genome represented by linkage groups, 1, 5 and 7 appeared to affect a greater number of traits than other genomic regions represented by linkage groups 2, 3 and 4. Results indicated that the mean expression of quantitative traits at segregating marker locus classes can be used to locate the genetic factors in lentil which influence the behavior of economically important traits.     

Yield stability of induced-early-maturing mutants of mungbean (Vigna radiata) and their use in a multiple-cropping system

The performance of seven mutants of mungbean along with parental types was studied at 41 different sites in three summer crop seasons from 1980 to 1982. The performance of mutants was also studied in spring in the fallow period preceding cotton, and in early summer in the fallow period between wheat harvest and rice/maize planting, to assess their suitability of growing as a catch-crop in these fallows.

The mutants yielded significantly higher and matured 2–4 weeks earlier than parental types, leaving sufficient time to sow the succeeding crops. The mutants were characteristically short-statured, and superior to their parents with respect to number of pods per plant, seed weight, harvest index and productivity per day, but similar in numbers of seeds per pod and seed protein content.

The stability of yield was estimated through regression analysis. Significant genotypic differences were observed among mutants and varieties. Some mutants were widely adapted whereas others performed better in favourable environments. The parental types tended to respond well under poor environments.

Owing to their higher yield potential, early and uniform maturity, and wide adaptability, four mutants were approved as commercial varieties in 1986. These mutants yield 30–50% higher than the parents, mature in 55–70 days, and are suited to both summer and spring crop seasons. Of these four mutants, two can be grown in the fallow period between wheat harvest and rice/maize planting. Because of their determinate plant type, non-shattering pod and top fruit-bearing habit, these mutants are also amenable to intercropping practices and mechanised harvesting operations.

The role of induced mutations for the improvement of mungbean is discussed.     

Determining the uniformity coefficient and water distribution characteristics of some sprinklers

The basic aim of the sprinkler irrigation method, as in other irrigation methods, is to apply irrigation water as uniformly as possible to the root zone. The uniform distribution of the applied water in sprinkler irrigation depends on factors such as sprinkler type, number and size of nozzles, arrangement of sprinklers, working pressure and the speed and direction of the wind. Sprinkler and lateral spacing should be determined by also taking the speed and direction of the wind into consideration. The aim of this study was to determine the application limits and the curves of water distribution under different working pressures, spatial arrangement and nozzle diameters under field conditions of some irrigation sprinklers which are widely used in Turkey. The objective was to determine the most appropriate system arrangement by using a computer program called CATCH3D. Five sprinklers were tested in the experimental area of Ondokuz Mayis University Campus and their water distribution characteristics identified. The most suitable operating parameters for Bereket 3: 12 x 18 m, Bereket 2: 12 x 18 m, Egeyildiz 6 x 18m, Goktepe 6 x 12 m and for Atesler sprinkler 12 x 18 m arrangement type were determined.