The availability of a genetically diverse gene pool is vitally important in varietal development. Molecular markers are being extensively utilized to explore the genetic diversity among native and exotic germplasm. This study was designed to reveal the genetic diversity and patterns of relationships among the 20 accessions/genotypes representative of basmati and non-basmati rice from the existing rice gene pool using RAPD markers. Employing RAPD, 17 decamer oligonucleotide primers directed the amplification of 116 fragments, out of which 101 were polymorphic (87.06%) while 15 fragments were monomorphic (12.93%). Similarity coefficients had ranged from 0.47 to 0.90. The average genetic similarity was calculated 0.68 (68%). In this study, the coarse rice genotypes showed more polymorphism (85.84%) than the fine rice genotypes (61.76%). Genotypes were clustered into 8 distinct groups: A, B, C, D, E, F, G, and H but two genotypes, i.e., Shadab and Kangni-27 showed divergence from all the genotypes of the groups. Therefore, these diverse genotypes may be included in future breeding programmes.
Six wheat genotypes (three female and three male) were crossed for the study of some quantitative traits in wheat. Analysis of variance showed a highly significant difference for all the characters except flag leaf area, which was significant. Testers revealed that LU26S was the best general combiner only for plant height. Mehraj showed a good general combining ability effect on plant height, flag leaf area, peduncle length, and 1000-grain weight. Farid 2006 was the best male parent as general combiner for plant height, peduncle length, spike length, number of grains per spike, and grain yield per plant. The wheat parental lines revealed that 9381 was the best general combiner for plant height, flag leaf area, peduncle length, 1000-grain weight, and grain yield per plant. Whereas 9428 was the best general combiner for flag leaf area, spike length, and number of spikelets per spike. Among crosses, LU26S × 9272, LU26S × 9381, Mehraj × 9272, and Mehraj × 9381 showed a significant effect of specific combining ability (SCA) on grain yield per plant. Other crosses with significant and positive SCA effects were LU26S × 9272 on plant height and 1000-grain weight grain yield per plant, LU26S × 9428 on peduncle length, and Mehraj × 9381 on plant height and grain yield per plant. These crosses with significant effects of general combining ability (GCA) on grain yield per plant can be used in the development of new varieties. These crosses with nonadditive genes would give transgressive segregants. For yield improvement, vigilant selection of the potent transgressive segregants through family selection would be valuable for yield enhancement. A total of 15 SSR primers of Xgwm series and 5 of X series were used to find out the codominant loci in the hybrid and single dominant loci in parents. Out of 15 primers only, Xgwm-314 gave the polymorphic banding pattern. This primer showed the polymorphic dominant loci in the parents (LU26S, Mehraj, 9272 and 9381) and codominant loci midway between these parents. Therefore, this SSR primer was used to confirm the two best performing hybrids (LU26S × 9272 and Mehraj × 9381) on the bases of positively significant effects of GCA and SCA on plant height, 1000-grain weight and grain yield per plant, and other economically important traits. The two hybrids namely LU26S × 9272 and Mehraj × 9381 can be used in the further breeding program for the development of high yielding varieties.
Cultivar mixtures have been suggested as ways to increase crop productivity. This field study was conducted to investigate the competition among five cultivated varieties of wheat (
Brassinolide influenced rice (
The biomass production (BP), the leaf age (LA), and the plant height (PH) as well as the quantitative trait loci (QTLs) associated with these traits were determined for F2:3 population derived from the cross of two contrasting maize (
MiRNAs belong to one type of noncoding RNAs involved in developmental regulation, genome maintenance, and defense in eukaryotes. In plants, the miRNAs are involved in many molecular interactions, including interfere with expression of mRNAs encoding factors that control developmental processes, stem cell maintenances, auxin responses, and other developmental and physiologic processes. In this paper, the molecular characterization and the functions of miRNAs on mediation of target gene silencing in plants have been overviewed. Further studies on the miRNAs will be helpful for elucidation of the molecular mechanism of post- transcriptional gene silencing in plants.
Based on the DNA sequence of
Mitogen-activated protein kinase (MAPK) cascade plays a central role in transfer information from diverse receptors/sensors to a wide range of cellular responses in plants. MAP kinases are organized into a complex network for efficient transmission of specific stimuli, including the abiotic stress signaling. In recent years, the mutants of loss-of-function and gain-of-function, and other additional tools are used to investigate the plant MAPK cascades. This review has summarized the recent progress on the MAPK cascade involved in mediation of the transduction of several pronounced abiotic stress signalings, such as salt, drought, low and high temperature, wound, hormone, and deficient nutrients. Currently, although part of the components of the MAPK cascade responding to the abiotic stresses have been identified, the integral molecular mechanisms of the abiotic stresses signaling transduction mediated via MAPK cascade are largely unknown and need to be elucidated further in the future.
Total RNA of
Flower development of
Primer pairs were designed to amplify the genomic DNA sequence of the farnesyl diphosphate synthase (
A selection test of four new flowering Chinese cabbage (
In this paper, four RNA extraction methods (CTAB method, TRIzol method, D326A reagent and RP3301 Kit) for walnut buds were compared by agarose gel electrophoresis and spectrophotometry, and the optimal method was verified further by Reverse transcription and PCR amplification (RT-PCR). There was a certain degree of degradation for the extracted RNA by CTAB method, TRIzol method and D326A reagent. Moreover, protein was found in the CTAB method. For the three unsatisfactory methods, longer operation time could be the main reason that RNA could not be separated in time with polyphenols, polysaccharides and other secondary metabolites. RP3301 kit was suitable for the RNA extraction from walnut buds with high purity, simplicity, innocuity and no degradation. This research will provide a fundamental basis for the cloning and expression analysis of genes and other follow-up tests.
To reduce nitrate leaching, the effects of three N-catch crops of sweet corn (
Effect of temperature and relative humidity on population dynamics of insect pests of mung bean was studied during mung bean growing season of 2005. Insect pests included thrips (
Two generations of
A new experiment on seed germination technique for
Average fruit weight, seed browning, flesh firmness, total soluble solids, internal browning, and skin blackening were used to determine the optimum harvesting time of ‘Wonhuwang’ pear. Pears for storage were picked three times at 5-day intervals before, during, and after estimated optimum harvesting date. Average fruit weight and seed browning degree were calculated at each picking time. Quality changes, internal browning, and skin blackening were employed to estimate the optimum harvest date. It was found that fruit quality parameters both at harvest and after storage depended on the stage of ripeness at which the pears were picked. Pears harvested earliest (H1) had the highest firmness both before and after storage and lost less percentage of their firmness during storage. The latest picked pears (H3) showed higher total soluble solids value and serious internal browning and skin blackening due to their over ripeness. Pears picked on the 15th of August (H2) had higher firmness and total soluble solids, lower extent of internal browning, and no skin blackening. Based on the changes in fruit firmness and physiologic disorder during ripening and storage, the optimal harvesting time for ‘Wonhuwang’ pear in Shijiazhuang area is around the 15th of August.