Summary The genomic DNAs of 42 Pisum sativum genotypes, representing four wild and cultivated subspecies were used as templates in RAPD reactions. Amplification with eight decamer primers generated 149 polymorphic products. Genetic similarities of RAPD profiles were estimated via a coefficient of Jaccard and then the data were processed by cluster analysis (UPGMA). Each genotype was clearly identified and separated from the others. Our results show that RAPD technology is a rapid, precise and sensitive technique for identification of pea genotypes. However, the phylogenetic relationships within the Pisum sativum, which we tested by bootstrap analysis (Wagner parsimony), must be interpreted with caution. 相似文献
The purpose of this study was to modify and calibrate the CERES-Sorghum water balance model for the dry, high radiation and windy conditions in an area in Southern Italy.
The equation for estimating potential evapotranspiration (E0) was substituted by another one, calibrated in the study site and expressed as a function of equilibrium evaporation and maximum vapour pressure deficit (defined as the difference between the saturation vapour pressure at maximum and at minimum temperatures).
To calibrate the E0 equation included in CERES-Sorghum, two drainage lysimeters, located at the Istituto Sperimentale Agronomico experimental farm, Foggia (Italy), were used to measure weekly evapotranspiration of well-watered, irrigated fescue grass, from 1976 to 1986.
A further drainage lysimeter, located in the same farm and cropped with well-watered grain sorghum (cv. NK 121) was used to calibrate the genetic coefficients input to the modified CERES-Sorghum model during the cropping seasons 1979 and 1980.
Simulated phenological dates (anthesis and maturity), grain yield, LAI, biomass and crop evapotranspiration were then compared with the measured ones in a fourth drainage lysimeter cropped with sorghum.
The modified model simulated grain yield accurately, but simulated daily evapotranspiration did not always match well the observed value, especially early in the crop cycle. Improvements are needed to the model in its simulation of soil evaporation and in the crop response function to temperature. 相似文献
Increasing irrigation costs and declining water availability compel producers to adapt irrigation strategies for maximum crop yield and water use efficiency. A field trial was conducted to observe the effects of various drip irrigation ratios (IR-0, IR-25, IR-50, IR-75 and IR-100) on water use efficiency (WUE), the irrigation water use efficiency (IWUE), lint yield, yield components and fibre quality at two upland cotton varieties during 2004 and 2005. WUE was found to increase from 0.62 to 0.71 kg m−3 as the irrigation water applied was reduced from 100 % to 75 % of soil water depletion. Deficit irrigation of cotton with drip irrigation at 75 % treatment level (IR-75) did not decrease seed cotton yield and yield components during 2 years, with the exception of the number of bolls in 2005. Among fibre quality parameters, no significant differences in fibre length, fineness, uniformity index and elongation were detected between the 100 % and 75 % irrigation levels in 2005. The results revealed that irrigation of cotton with a drip irrigation method at 75 % level had significant benefits in terms of saved irrigation water without reducing yield, and high WUE indicated a definitive advantage of employing deficit irrigation under limited water supply conditions. 相似文献
The mechanism that controls the proportion of cannabichromene (CBC), a potential pharmaceutical, in the cannabinoid fraction
of Cannabis sativa L. is explored. As with tetrahydrocannabinol (THC) and cannabidiol (CBD), CBC is an enzymatic conversion product of the precursor
cannabigerol (CBG). CBC is reported to dominate the cannabinoid fraction of juveniles and to decline with maturation. This
ontogeny was confirmed in inbred lines with different mature chemotypes. A consistent CBC presence was found in early leaves
from a diverse clone collection, suggesting that CBC synthase is encoded by a fixed locus. Morphological variants possessing
a ‘prolonged juvenile chemotype’ (PJC), a substantial proportion of CBC persisting up to maturity, are presented. PJC is associated
with a reduced presence of floral bracts, bracteoles, and capitate-stalked trichomes. Genetic factors causing these features
were independent of the allelic chemotype locus B that was previously postulated and regulates THC and CBD synthesis and CBG accumulation. In contrast to previously described
Cannabis chemotypes, the cannabinoid composition of PJCs showed plasticity in that reduced light levels increased the CBC proportion.
The ability of PJC plants to enable the production of pharmaceutical raw material with high CBC purity is demonstrated. 相似文献
The establishment of water-saving crop planning is an inevitable choice of the water-saving agriculture for the water-deficiency region in the arid and semiarid Loess Plateau of China and the world. The water-saving crop planning refers to the planting structure that centres the adjustment of the crop's adaptation to water, the optimization of temporal and spatial layout for crops, the local natural resources, marketing resources, human resources and financial input to enable region or basin with limited water resources to achieve the maximum economic, social and ecological benefits of planting industry under certain technology and economy. After the analysis on the research progress of optimization theory, optimization goals, optimization methods of water-saving cultivation structure and macro-control measures, it is pointed out that the main deficiencies of the current research of water-saving cultivation pattern optimization are lacking of a strong theoretical basis, and the immaturity of optimization technologies. The future crucial research direction will focus on five aspects such as the special optimization theory system, the division methods by studying the watershed unit and using 3S technology, optimization model based on multi-objective evolutionary algorithm, evaluation of rationality and macro-control measures on the basis of the public participation. 相似文献
A major factor affecting spring canola (Brassica napus) production in Canada is killing frosts during seedling development in the spring and seed maturation in the fall. The objective
of this study was to explore the possibility of producing spring canola lines with mutations that have altered biochemical
pathways that increase cold tolerance. The approach was to generate UV point mutations in cultured microspores followed by
chemical in vitro selection of individual mutant microspores or embryos resulting in measurable alterations to various biochemical
pathways with elevated levels of key defense signaling molecules such as, salicylic acid (SA), p-Fluoro-d,l-Phenyl Alanine (FPA), and jasmonic acid (JA). In addition, since proline (Pro) is known to protect plant tissues in the cold-induced
osmotic stress pathway, mutants that overproduce Pro were selected in vitro by using three Pro analogues: hydroxyproline (HP),
azetidine-2-carboxylate (A2C); and, 3,4-dehydro-d,l-proline (DP). Of the 329 in vitro selected mutant embryos produced, 74 were identified with significant cold tolerance compared
to their donor parents through indoor freezer tests at −6°C, and 19 had better winter field survival than winter canola checks. All chemically selected mutant doubled haploids with increased
cold tolerance compared well with parent lines for all seed quality and agronomic parameters. Development of increased frost
tolerant cultivars should allow for spring canola to be produced in western Canada without compromising seed quality. 相似文献
Popping expansion volume (PEV) is the most important quality trait in popcorn, while its germplasm is inferior to normal dent/flint
corn in yield. In this study, 259 F2:3 families, developed from the cross between a dent corn inbred Dan232 and a popcorn inbred N04, were evaluated for their PEV,
grain weight per plant (GWP) and 100-grain weight (100 GW) in two environments. The genetic relationship between PEV and GWP,
and 100 GW on individual gene loci were evaluated using unconditional and conditional QTL mapping methods. In total, five,
one and three unconditional QTL were identified for PEV, GWP, and 100 GW, respectively. The positive alleles of all QTL for
PEV were from N04, while positive alleles of all QTL for GWP and 100 GW were from Dan232. In conditional mapping, one and
two QTL failed to be detected, and all four additional QTL were detected. Nevertheless, three QTL were identified, which controlled
PEV independently from GWP/100 GW. They seemed to be potential candidates in popcorn breeding to increase PEV without decreasing
GWP/100 GW. The results suggested that for significantly correlated traits, the conditional QTL mapping method could be used
to dissect the genetic interrelationship between traits at the level of individual QTL, as well as reveal additional QTL that
were undetectable by unconditional mapping. 相似文献
Ten SSR loci, previously developed for grapevine, were analyzed to evaluate the genetic variability, cultivar relatedness, and parentage in a collection of 61 autochthonous Vitis vinifera cultivars from Tunisia.The number of alleles per locus ranged from 6 to 11, while the number of genotype patterns varied between 10 and 21. The expected heterozygosity varied between 0.621 and 0.855 and the observed heterozygosity was higher than 0.9 at 4 loci (VVMD28, VVMD5, VVIP31 and VVS2) indicating that the SSRs were highly informative.Cluster analysis using unweighted pair group method with arithmetic averaging (UPGMA) suggested 14 groups among studied cultivars and 53 grapevine denominations out of 61 were unequivocally distinguished, with all accessions showing at least one-specific combination of alleles.On the other hand, in order to overcome the existing confusion in Tunisian grapevine nomenclature, of the analyzed homonymous pairs of cultivars, only ‘Balta 2’ and ‘Balta 3’ have shown identical allelic profiles, consistent with their being the same genotype. Hence, nomenclature distinction is meaningless and only one denomination should be retained.Due to the high overall power of exclusion (Q) (greater than 99.99%) and to the absence of null alleles, the set of microsatellite loci used is appropriate to determine parentage in Tunisian grapevines beyond any reasonable doubt. The analysis of fingerprints indicated that the Tunisian grape vines have evolved through out crossing between five possible parents: Balta 1, Beldi Baddar, Beldi Rafraf, Beldi Local Rafraf and Khedhiri 3. 相似文献