An overview of the potentials of natural rubber (Hevea brasiliensis) engineering for the production of valuable proteins

Nigeria has in recent times exhibited great commitment to the use of biotechnology as a tool to enhance agricultural and general socioeconomic development. Plant biotechnology and genetic engineering have led to the production of various pharmaceutical proteins from plant sources. Plantsare potential bio-farming factories because they provide an inexpensive and convenient system for the large scale production of valuable recombinant proteins. The objective of this paper is to highlight theprospects and potentials of transgenic rubber plant as a unique protein factory which will act as additional source of income to the rubber farmer especially in Nigeria. Rubber has the advantage of having continuous harvesting from same tree for a minimum of twenty years. The International Rubber Research Organizations have successfully developed transgenic rubber plants that produce foreign proteins of potential commercial value. Among such routines is an antibody and human serum albumin. Tapping rubber trees for valuable proteins will be more profitable compared to other options. The technologies have been developed and only needs to be adapted to our local conditions. It is hoped that this paper will be instructive to rubber farmers, policy makers, executors of policies or citizens wishing to join the Nigerian rubber farmers in their bid to increase their prosperity or alleviate their poverty

QTL analysis for resistance to foliar damage caused by Thrips tabaci and Frankliniella schultzei (Thysanoptera: Thripidae) feeding in cowpea [Vigna unguiculata (L.) Walp.]

Three quantitative trait loci (QTL) for resistance to Thrips tabaci and Frankliniella schultzei were identified using a cowpea recombinant inbred population of 127 F2:8 lines. An amplified fragment length polymorphism (AFLP) genetic linkage map and foliar feeding damage ratings were used to identify genomic regions contributing toward resistance to thrips damage. Based on Pearson correlation analysis, damage ratings were highly correlated (r ≥ 0.7463) across seven field experiments conducted in 2006, 2007, and 2008. Using the Kruskall–Wallis and Multiple-QTL model mapping packages of MapQTL 4.0 software, three QTL, Thr-1, Thr-2, and Thr-3, were identified on linkage groups 5 and 7 accounting for between 9.1 and 32.1% of the phenotypic variance. AFLP markers ACC-CAT7, ACG-CTC5, and AGG-CAT1 co-located with QTL peaks for Thr-1, Thr-2, and Thr-3, respectively. Results of this study will provide a resource for molecular marker development and the genetic characterization of foliar thrips resistance in cowpea

The GCP molecular marker toolkit, an instrument for use in breeding food security crops

Crop genetic resources carry variation useful for overcoming the challenges of modern agriculture. Molecular markers can facilitate the selection of agronomically important traits. The pervasiveness of genomics research has led to an overwhelming number of publications and databases, which are, nevertheless, scattered and hence often difficult for plant breeders to access, particularly those in developing countries. This situation separates them from developed countries, which have better endowed programs for developing varieties. To close this growing knowledge gap, we conducted an intensive literature review and consulted with more than 150 crop experts on the use of molecular markers in the breeding program of 19 food security crops. The result was a list of effectively used and highly reproducible sequence tagged site (STS), simple sequence repeat (SSR), single nucleotide polymorphism (SNP), and sequence characterized amplified region (SCAR) markers. However, only 12 food crops had molecular markers suitable for improvement. That is, marker-assisted selection is not yet used for Musa spp., coconut, lentils, millets, pigeonpea, sweet potato, and yam. For the other 12 crops, 214 molecular markers were found to be effectively used in association with 74 different traits. Results were compiled as the GCP Molecular Marker Toolkit, a free online tool that aims to promote the adoption of molecular approaches in breeding activities

Genomics-assisted breeding in four major pulse crops of developing countries: present status and prospects

The global population is continuously increasing and is expected to reach nine billion by 2050. This huge population pressure will lead to severe shortage of food, natural resources and arable land. Such an alarming situation is most likely to arise in developing countries due to increase in the proportion of people suffering from protein and micronutrient malnutrition. Pulses being a primary and affordable source of proteins and minerals play a key role in alleviating the protein calorie malnutrition, micronutrient deficiencies and other undernourishment-related issues. Additionally, pulses are a vital source of livelihood generation for millions of resource-poor farmers practising agriculture in the semi-arid and sub-tropical regions. Limited success achieved through conventional breeding so far in most of the pulse crops will not be enough to feed the ever increasing population. In this context, genomics-assisted breeding (GAB) holds promise in enhancing the genetic gains. Though pulses have long been considered as orphan crops, recent advances in the area of pulse genomics are noteworthy, e.g. discovery of genome-wide genetic markers, high-throughput genotyping and sequencing platforms, high-density genetic linkage/QTL maps and, more importantly, the availability of whole-genome sequence. With genome sequence in hand, there is a great scope to apply genome-wide methods for trait mapping using association studies and to choose desirable genotypes via genomic selection. It is anticipated that GAB will speed up the progress of genetic improvement of pulses, leading to the rapid development of cultivars with higher yield, enhanced stress tolerance and wider adaptability

Legume Genomics and Breeding

This chapter contains sections titled; Introduction; Constraints in Crop Production; Genomic Resources in Legumes;Trait Mapping and Marker-Assisted Selection; Summary and Prospects; Acknowledgments; Literature Cite

Genetic mapping of quantitative trait loci (QTLs) with effects on resistance to flower bud thrips (Megalurothrips sjostedti) identified in recombinant inbred lines of cowpea (Vigna unguiculata (L.) Walp)

The first major insect pest of cowpea at reproductive stage is the flower bud thrips (FTh), which, if not controlled, is capable of causing significant grain yield reduction. Breeding for resistance to FTh incowpea has been hindered by the quantitative nature of the resistance, and the breakdown of resistance under high insect infestation. The purpose of this study was to use molecular markers toidentify genetic loci associated with the expression of resistance to FTh. A set of 92 recombinant inbred lines (RILs) was generated from a cross between susceptible and resistant lines. One hundred andthirty nine markers [134 Amplified Fragment Length Polymorphism (AFLP) and 5 cowpea derived microsatellites] were used to construct a linkage map using this set of RILs. The linkage map spans1620 cM of the cowpea genome and markers were distributed in 11 linkage groups. Average distance between adjacent markers was 9.6 cM. There were significant associations between 23 DNA markersand resistance to flower bud thrips (

Genetic mapping of quantitative trait loci (QTLs) with effects on resistance to flower bud thrips (megalurothrips sjostedti) identified in recombinant inbred lines of cowpea (Vigna unguiculata (L.) Walp)

Open Access JournalThe first major insect pest of cowpea at reproductive stage is the flower bud thrips (FTh), which, if not controlled, is capable of causing significant grain yield reduction. Breeding for resistance to FTh in cowpea has been hindered by the quantitative nature of the resistance, and the breakdown of resistance under high insect infestation. The purpose of this study was to use molecular markers to identify genetic loci associated with the expression of resistance to FTh. A set of 92 recombinant inbred lines (RILs) was generated from a cross between susceptible and resistant lines. One hundred and thirty nine markers [134 Amplified Fragment Length Polymorphism (AFLP) and 5 cowpea derived microsatellites] were used to construct a linkage map using this set of RILs. The linkage map spans 1620 cM of the cowpea genome and markers were distributed in 11 linkage groups. Average distance between adjacent markers was 9.6 cM. There were significant associations between 23 DNA markers and resistance to flower bud thrips (P<0.05) using single marker analysis. QTLs with effects on resistance were detected in five linkage groups. The QTL on linkage group 3 explained 32.0% of the variation for resistance while all the five QTLs together explained 77.5%

Genetic analysis of resistance to flower bud thrips (Megalurothrips sjostedti) in cowpea (Vigna unguiculata [L.] Walp.)

Cowpea is an important legume in sub-Saharan Africa where its protein rich grains are consumed. Insect pests constitute a major constraint to cowpea production. Flower bud thrips (FTh) is thefirst major pest of cowpea at the reproductive stage and if not controlled with insecticides is capable of reducing grain yield significantly. Information on the inheritance of resistance to FTh is required to facilitate breeding of resistant cultivars. The genetics of resistance was studied in crosses of four cowpea lines. Maternal effect was implicated while frequency distributions of the F2 and backcross generations suggest quantitative inheritance. Additive, dominance and epistatic gene effects made large contributions and since improved inbred lines are the desired product, selection should not be too severe in the early generations to allow for desirable gene recom-bination. This study suggested that some of the genes involved in the control of resistance to FTh are different in TVu1509 and Sanzi. Broad sense heritability ranged from 56% to 73%. Choice of maternal parent in a cross will be critical to the success of resistance breeding