Bulb onion (Allium cepa), which belongs to the family Amaryllidaceae, is one of the oldest vegetative crops known to humans. Despite its high economic value, only a few reports are available on the use of molecular markers in genetic diversity analysis of Allium cepa for its improvement. Molecular genetic markers have been widely used as powerful tools for analyzing the plant genome. In particular, Microsatellites or simple sequence repeats (SSRs) markers are tandem repeats of one to six bp in length and have been proven to be the most powerful polymerase chain reaction (PCR)-based DNA markers in plant diversity analysis. In this study, the genomic DNA was isolated from different Allium cepa lines. The ESTs and gDNA sequences of onion were collected from National Center for Biotechnology information. The SSRs with two to five motifs over a length of 12 bp, were identified using SSRIT (Gramene) software. The PCR products of 100 to 350 bp in length containing SSRs, primers was designed using Primer3 with lengths of 20 to 24 bp and a melting temperature of 60℃. The SSR markers with high polymorphism-information content (PIC) levels was useful for collecting progeny with high genetic homogeneity for onion breeding, and to obtain representative marker sets for genetic tests. The SSR Finder program and the developed SSR markers could be a useful resource for genetic diversity and purity testing in onion.

Onion is one of the most widely consumed vegetables. There are many cultivars, which are grouped according to skin color as yellow, white or red. Onions can also be classified as sweet or non-sweet. Their importance in cooking comes from their typical taste and flavour. The sugars, pyruvic acid accumulation and transcript level of some transcription factors involved in the biosynthesis of high sugars and pyruvic acid was analyzed at different stages of bulb onion (Allium cepa) growing under light and dark condition using High Performance Liquid Chromatography (HPLC) and Quantitative real time PCR. A genetic map and cultivar lines 36101and 36122 were used to identify transcription factors controlling pungency and sugar. We compared 2 different lines for low pungency and high sugars during water and photoperiod stress, which showed significant positive phenotypic and genetic correlations. These results could be presumably used as useful information to obtain onion varieties rich in sugars.

Fortification with vitamins in crops like rice is a continuing endeavor for geneticists and rice breeders. Tryptophan is one of the essential amino acids needed in human diet. In this study, we developed rice mutant lines using ethyl methane sulfonate (EMS) treatment in Korean cv. Donganbyeo and candidate rice lines were selected by insensitivity to the tryptophan analog, 5-methyltryptophan. One of the mutants has a 20-25 fold higher tryptophan level in mature seeds than wild type. To identify the mutations in anthranilate synthase genes, OASA1 and OASA2 sequences were generated. Moreover, mRNA expression levels of tryptophan biosynthesis related genes were examined. To further qualify the tryptophan fortification in rice, comparative assessment of cooking and eating quality was conducted with mutant lines and wild type. The moisture, viscosity, taste quality, protein content, amylose content and amino acid composition were similar with wild type. However, tryptophan contents in the mutant lines were higher than wild type as we targeted. The mutation present in AS gene of 5MT resistant rice may prove useful for the generation of crops with increased tryptophan contents and the mutation differences in AS sequences can be used for selection of mutant lines with high tryptophan level from large population.

There is a great consideration on rice eating quality aside from improving its tolerance to various stresses. High yielding and pest and disease tolerant rice is highly desirable but it is more commercially important if it also has a high eating quality. There are various factors contributing to the good eating quality of rice. This study focuses on modifying the expression of GBSS1 genes which are responsible for amylopectin and amylose synthesis in rice by using RNAi and antisense techniques. We have developed 40 transgenic plants with RNAi-GBSS1 gene and 60 transgenic lines with antisense-GBSS1 gene. The transgenic plants show diverse amylose contents in rice seed. We selected candidate lines according to PCR, RNA expression and amylose contents. A semi-quantitative RT-PCR was carried out to measure the expression level of GBSS1 gene at several time points after the flowering of transgenic plants. The expression level of GBSS1 gene in rice grains decreases over time and the mRNA expression among the transgenic plants were lower compare to its wild type. In the SEM analysis, the starch granule of wild type Gopumbyeo has very large structures accompanied with small ones around the area. However, the starch structures in transgenic plants were smaller and more uniform in size and shape throughout the viewing area

In spite of the overwhelming number of cysteine proteases in plants, only a few were substantially investigated. Papain-like cysteine proteases (PLCPs) are commonly implicated to disease immunity in some key pathosystems in plants, such as in tomato – Cladosporium fulvum, potato/tomato – phytopthora infestans, and Arabidopsis – Ralstonia solanacearum, among the few others. This study demonstrates the function of cysteine protease gene cloned form Brassica rapa (BrCP) related to resistance to Xanthomonas oryzae pv. oryzae in transgenic rice lines. The cysteine protease-encoding full-length cDNA was identified and characterized using web-based tools. The gene is 2,267 bp in size with an open reading frame of 1,365 bp that encodes predicted polypeptide of 455 amino acids. Blast analysis of the conserved domain of the gene confirmed its affinity to Peptidase_CIA family. Full-length cDNA of PLCP in Brassica rapa was then cloned and co-overexpressed in rice with HPT marker. Introgression of the gene was confirmed in the transformants through genomic PCR assay. RT-PCR analysis showed that the gene was constitutively expressed and present in all tissues. The overexpression rice lines exhibited an enhanced resistance when screened with four Korean Xoo isolates.

Purpose - The study aimed to evaluate the market opportunities and constraints confronting resource-poor pig farmers in South Africa. Research design, data, and methodology - Information was collected from 292 households in three municipalities through interviews with key informants. The data collected included socio- economic characteristics, major market channels, prices for different pig classes, average weight of the pigs on sale, number of pigs sold annually, and preferred meat quality attributes. Results - In Ngqushwa, 96% of respondents sold pigs as compared to Elundini (81%) and Ntabankulu (65%). Less resource- poor households and those with market-oriented production had large herdsizes (P < 0.05) when compared to more resource-poor farmers. The probability of selling pigs was high for the backyard production system and educated farmers. For all farmers, opportunities included high pork demand, good prices, employment creation, and a niche market for organically produced indigenous pork. Constraints include disease, feed shortages for large herds, distances to formal markets, lack of training, and drugs. Conclusions - Constraints outnumbered opportunities for the resource-poor pig farmers

The THO/TREX complex mediates the transport of nascent mRNAs from the nucleus towards the cytoplasm in animals, and it has a role in small RNA-dependent processes in plants. Here we describe five mutant alleles of Arabidopsis thaliana THO2, whichencodes a core subunit of the plant THO/TREX complex. tho2 mutants present strong developmental defects resembling those in plants compromised in microRNA (miRNA) activity. In agreement, not only the levels of siRNAs, but also of mature miRNAs were reduced in tho2 mutants. As a consequence miRNA target mRNAs accumulated to higher levels than in wild type. Yeast two hybrid experiments showed that THO2 does not seem to interact with any of the known miRNA biogenesis components, implying a more indirect role of THOs in small RNA biogenesis. We also detected alterations in the splicing pattern of genes encoding Serine/Arginine-rich proteins in tho2 mutants, suggesting a previously unappreciated role of the THO/TREX complex in alternative splicing.

In U.S.A. maize breeding, exotic germplasm is considered as high-risk and usually introduced by backcrossing specific traits into elite lines. The U.S.A. maize germplasm base is narrow. Only a few open-pollinated varieties are well represented in current programs. Currently, the barrier in using of exotic germplasm in the U.S.A is less formidable than in the 1980s. The major reason is that U.S.A materials are now used in tropical breeding to accelerate earlier maturity and lodging resistance. These exotic materials, developed with U.S.A germplasm, are being introduced back into the U.S.A.Since1994, the ARS-led Germplasm Enhancement of Maize (GEM) project has sought to help broaden the genetic base of America’s corn crop by promising exotic germplasm and crossing it with domestic lines. New hybrids derived from such crosses have provided corn researchers and the producers. These may include improved or alternative native source of resistance to insect pests such as corn rootworms and diseases like northern leaf blight. GEM’s aim is to provide source of useful genetic maize diversity to help the producers to reduce risks from new or evolving insect and disease threats or changes in the environment or respond to new marketing opportunities and demand. During the 2009 growing season, the Ames (Iowa) and Raleigh (North Carolina) locations managed or coordinated evaluations on 17,200 nursery plots as well as 14,000 yield trial plots in Ames and 12,000 in Raleigh. A new “allelicdiversity” study is devoted to exploring and capturing the genetic variation represented by over 300 exotic corn races. Since 2001, GEM has released 221 new corn lines to cooperators for further development into elite commercial new hybrids. GEM has already identified about 50%-tropical, 50%-temperate families tracing primarily to tropical hybrids that are competitive with commercial checks. In North Carolina State University program, they have examined the potential of tropical inbredand hybrids for U.S.A. breeding by crossing temperate-adapted, 100%-tropical lines to U.S.A hybrids. There should be favorably unique alleles or genomic regions in temperate germplasm that can be helpful in tropical maize improvement as well as utilization of tropical lines in temperate areas.

UDP-glucose 4-epimerase catalyzes the reversible conversion of UDP-glucose to UDP-galactose. The gene, named BrUGE1, isolated from a Chinese cabbage composes of a total length of 1,328 bp that contains a single open reading frame (ORF) of 1,056 bp which encodes a polypeptide of 351 amino acid residues with a calculated mass of 39.0 kDa. Expression analysis showed that BrUGE1 is tissue specific and highly expressed in stem of rice plant. Interestingly, BrUGE1 mRNA was highly accumulated by drought stress with significantly higher amount of soluble sugar. Morphological evaluation showed an increase in yield and yield components compared to the wild type. Moreover, a better growth performance on galactose as well as higher UGE1 expression was observed in transgenic rice lines than in wild type. In the Ubi-1::BrUGE1 lines, the increase of UGE1 expression was apparently sufficient to overcome the toxic effects of galactose. Taken together, the Ubi-1::BrGUE1 rice lines increased yield probably by increasing the rate of filled grains. The enhanced drought tolerance may be due to the induction of soluble sugar which may act as osmolyte to compensate dehydration during drought stress.

Bacterial blight is a serious problem of rice in irrigated and rainfed lowlands. It is caused by Xanthomonas oryzae pv. oryzae (Xoo) which is represented by many pathotypes, making it difficult to control. Plant proteases are important players in immunity acting either in the execution of attack, in signaling cascade or in perception of invader. This study demonstrates the response of cysteine protease (CP) upon interaction with the pathogen. The cysteine protease encoding full-length cDNA was identified and characterized using web-based tools. Conserved domain of the gene revealed its affinity to Peptidase_CIA family. The full-length cDNA of CP in Brassica rapa was then cloned and overexpressed in rice. Insertion of gene was verified in the transformants through PCR assay. Spatiotemporal expression of the gene was performed in transgenic rice. To evaluate the resistance of CP-overexpression lines to Xoo, transgenic plants were inoculated with two races of Xoo. In planta analysis of enzymatic activity of CP was also performed before and after infection by the pathogen.

The transport of nascent messenger RNA from the nucleus to the cytoplasm is mediated by the THO/TREX complex and is evolutionary conserved from yeast, metazoa and humans. However, in plants, it is still yet unclear if the similar mechanism of transport exists. Here we identified and characterized a mutant gene, AtTHO2, a putative Arabidopsis thaliana THO2 component protein, homologous to yeast THO2 of the THO/TREX pathway required for mRNA transport. The mutation from this gene resulted to various developmental defects that include semi-dwarfism and abnormal floral development which further leads to sterility. Gene expression analysis revealed that AtTHO2 is expressed in all organs and pollen developmental stages. In addition, the homozygote progeny of null mutants did not persist until mature stage. These results suggest an indispensable role of AtTHO2 in the development of Arabidopsis. Differential gen expression and silencing were also observed between the null mutants and wild type depending on T-DNA insertion. Furthermore, alternative splicing which was tightly linked with the THO/TREX pathways was also defective on AtTHO2 and null mutants. A similar pattern of defect in SR34a was observed in the AtTHO2 and null mutants. In terms of microRNA biosynthesis, no significant differences were seen on the wild-type and mutant plants; however this data should be validated. Thus this work provides some evidences that a similar THO/TREX complex exist in plants and gave a foundation for further studies on the mechanism of nuclear export in plants.

A diverse number of genes are involved in the floral transition and development to ensure the proper timing on the switch from vegetative to reproductive development in Arabiodopsis. MADS-box genes play a major role in floral development especially in the case of vernalization process, In this study we mapped a mutation in MAF5 encoding a MADS-domain protein which was reported to be up-regulated during vernalization and regulates flowering time. The mutant in MAF5 showed several pleiotropic phenotypes that includes semi-dwarfism, delayed senescence and abnormal pollen phenotype, High percentages of vacuolated and aborted pollen phenotype were observed in the mutant plant. Transmission efficiency showed that mutation from this gene was defective in both male and female gametes. Furthermore, gene expression analysis revealed that this gene was predominantly expressed in reproductive organs and gave a strong expression in the mature pollen which coincides with the defect in pollen phenotype. The results from this study provide some evidences on the additional role of MAF5 in pollen development however more specific approaches should be done to determine the specific stages of pollen development altered in this mutant.

UDP-glucose 4-epimerase (UGE) catalyzes the reversible conversion of UDP-glucose to UDP-galactose. The gene, named BrUGE1, isolated from a Chinese cabbage had a total length of 1,328 bp that contains a single open reading frame (ORF) of 1,056 bp which encodes a polypeptide of 351 amino acid residues with a calculated mass of 39.0 kDa. Sequence analysis of BrUGE1 protein has the characteristic of an active site tetrad and NAD-binding motif (typically TGXXGXXG) of the extended short chain dehydrogenase/ reductase (SRD) superfamily. Expression analysis showed that BrUGE1 is tissue specific and highly expressed in stem of rice plant. Interestingly, BrUGE1 mRNA was highly accumulated by drought stress with significantly higher amount of soluble sugar. Morphological evaluation showed an increase in yield by 27%. Panicle length, number of productive tillers/hill, and filled spikelets were significantly increased by 17~20% compared to the wild type Gopum. Moreover, the growth of the wild type Gopum seedlings on galactose was increasingly inhibited with a decrease in UDP-glc epimerase 1 expression compared to the transgenic rice lines. In the Ubi-1::BrUGE1 lines, the increase of UDP-glc epimerase 1 expression was apparently sufficient to overcome the toxic effects of galactose. Taken together, the Ubi-1::BrGUE1 rice lines increased yield probably by increasing the rate of filled grains. The enhanced drought tolerance may be due to the induction of soluble sugar which may act as osmolyte to compensate dehydration during drought stress.

The amount of genetic variability of a species is essential for its survival and adaptation in different environments, and studies of genetic diversity using molecular markers are necessary to understand the genetic structure of a population and to orientate effective strategies of germplasm conservation. The aim of current study was to determine the SSR markers that can be used rapidly and reliably to evaluated the pepper of Bulgaria landraces, and applied the markers to assement of introduce genetic diversity of the pepper germplasm. We used 22 polymorphic microsatellite markers to analysis of genetic diversity within 61 pepper collection of Bulgaria landraces germplasm, all SSR primers pairs produced 80 polymorphic and reproducible amplification fragments. An average value of polymorphic information contents (PIC) were 0.334 with a range of 0.061 to 0.63. The mean values of observed (HO) and expected heterozygosity (HE) were 0.383 and 0.154, respectively, indicating a considerable amount of polymorphism within this collection. A genetic distance-based phylogeny grouped into three distinct groups, which was the landrace, moderate and wilde type, genetic distance (GD) value was 0.540. An average day of flowering time was 53 days with a range of 45 to 60 days. The everage od fruit length and width were 9.38cm with a range 2.1 to 23.6cm, and 3.51cm with a range 0.6 to 8.9cm, respectively. Molecular data were complemented with morphological measurements according to the descriptor list for the pepper collection of Bulgaria landraces germplasm.

For QTL analysis of agronomic traits based on cultivation of low and high altitude locations, BC1 F5 181 lines were developed from a cross of Tongil type Gayabyeo and japonica Chhomrong originated from Nepal. Plant materials were grown in both of low altitude area of Milyang, Korea and high altitude area of Khumaltar, Nepal. In QTLs analysis, a total of 42 QTLs were detected in days to flowering, culm length, panicle length, number of panicles/hill, panicle exertion, and spikelet ripening ratio. Although many of the QTLs were coincided between the two locations of Korea and Nepal, several QTLs were revealed as location specific in high altitude area of Khumaltar. Especially, the regions harboring marker RM489-RM14281 on chromo- some 3, RM5642-RM19049 on chromosome 5, and RM2854-RM6696 on chromosome 12 where QTLs were clustered and coincided between the two locations are considered as positive target regions for environmental independent traits. Furthermore, high rate of location specific QTLs such as panicle exertion and spikelet ripening ratio could be considered carefully for understanding the mechanism of cold tolerance based on cultivation of different altitude location.