Peanut is a legume crop that belongs to the family of Fabaceae, genus Arachis, and botanically named as Arachis hypogaea. Peanuts are consumed in many forms such as boiled peanuts, peanut oil, peanut butter, roasted peanuts, and added peanut meal in snack food, energy bars and candies. Peanuts are considered as a vital source of nutrients. Nutrition plays an important role in growth and energy gain of living organisms. Peanuts are rich in calories and contain many nutrients, minerals, antioxidants, and vitamins that are essential for optimum health. All these biomolecules are essential for pumping vital nutrients into the human body for sustaining normal health. This paper presents an overview of the peanut composition in terms of the constituent biomolecules, and their biological functions. This paper also discusses about the relationship between consumption of peanuts and their effect on human metabolism and physiology. It highlights the usefulness of considering peanuts as an essential component in human diet considering its nutritional values.

Peanut genotypes from the US mini-core collection were analysed for changes in leaf proteins during reproductive stage growth under water-deficit stress. One-and twodimensional gel electrophoresis (1-and 2-DGE) was performed on soluble protein extracts of selected tolerant and susceptible genotypes. A total of 102 protein bands/ spots were analysed by matrix-assisted laser desorption/ ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and by quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS) analysis. Forty-nine nonredundant proteins were identified, implicating a variety of stress response mechanisms in peanut. Lipoxygenase and 1L-myo-inositol-1-phosphate synthase, which aid in interand intracellular stress signalling, were more abundant in tolerant genotypes under water-deficit stress. Acetyl-CoA carboxylase, a key enzyme of lipid biosynthesis, increased in relative abundance along with a corresponding increase in epicuticular wax content in the tolerant genotype, suggesting an additional mechanism for water conservation and stress tolerance. Additionally, there was a marked decrease in the abundance of several photosynthetic proteins in the tolerant genotype, along with a concomitant decrease in net photosynthesis in response to water-deficit stress. Differential regulation of leaf proteins involved in a variety of cellular functions (e.g. cell wall strengthening, signal transduction, energy metabolism, cellular detoxification and gene regulation) indicates that these molecules could affect the molecular mechanism of water-deficit stress tolerance in peanut.

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Knowledge of genetic diversity, population structure, and degree of linkage disequilibrium (LD) in target association mapping populations is of great importance and is a prerequisite for LD-based mapping. In the present study, 96 genotypes comprising 92 accessions of the US peanut minicore collection, a component line of the tetraploid variety Florunner, diploid progenitors A. duranensis (AA) and A. ipae¨nsis (BB), and synthetic amphidiploid accession TxAG-6 were investigated with 392 simple sequence repeat (SSR) marker bands amplified using 32 highly-polymorphic SSR primer pairs. Both distance-and model-based (Bayesian) cluster analysis revealed the presence of structured diversity. In general, the wild-species accessions and the synthetic amphidiploid grouped separately from most minicore accessions except for COC155, and were eliminated from most subsequent analyses. UPGMA analysis divided the population into four subgroups, two major subgroups representing subspecies fastigiata and hypogaea, a third group containing individuals from each subspecies or possibly of mixed ancestry, and a fourth group, either consisting of COC155 alone if wild species were excluded, or of COC155, the diploid species, and the synthetic amphidiploid. Modelbased clustering identified four subgroups-one each for fastigiata and hypogaea subspecies, a third consisting of individuals of both subspecies or of mixed ancestry predominantly from Africa or Asia, and a fourth group, consisting of individuals predominantly of var fastigiata, peruviana, and aequatoriana accessions from South America, including COC155. Analysis of molecular variance (AMOVA) revealed statistically-significant (P \ 0.0001) genetic variance of 16.87% among subgroups. A total of 4.85% of SSR marker pairs revealed significant LD (at r 2 C 0.1). Of the syntenic marker pairs separated by distances \ 10 cM, 11-20 cM, 21-50 cM, and [ 50 cM, 19.33, 5.19, 6.25 and 5.29% of marker pairs were found in strong LD (P B 0.01), in accord with LD extending to great distances in self pollinated crops. A threshold value of r 2 [ 0.035 was found to distinguish mean r 2 values of linkage distance groups statistically from the mean r 2 values of unlinked markers; LD was found to extend to 10 cM over the entire minicore collection by this criterion. However, there were large differences in r 2 values among marker pairs even among tightly-linked markers. The implications of these findings with regard to the possibility of using Vikas Belamkar-This work was performed in partial fulfillment of the requirements for the Master of Science degree.

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G enetic variability is key to progress in crop improvement programs. However, the cultivated tetraploid peanut (Arachis hypogaea L.) has limited genetic variability, which has been explained as the result of a genetic bottleneck resulting from a single domestication event approximately 3500 yr ago (Simpson et al., 2002). Recent studies by Milla et al. (2005) using amplifi ed fragment length polymorphism (AFLP) verifi ed previous fi ndings by Kochert et al. (1996) that limited molecular polymorphism was found in the cultigen. In addition to paucity of genetic variation in the species, commercial peanut breeding programs further reduced genetic variation due to the predominance of few common elite parents, for example 'Dixie Giant' and 'Small White Spanish-1' (Knauft and Gorbet, 1989), in the ancestry of many varieties. The consequence is a reduced level of exploitable

Background: Transcriptome expression analysis in peanut to date has been limited to a relatively small set of genes and only recently has a significant number of ESTs been released into the public domain. Utilization of these ESTs for oligonucleotide microarrays provides a means to investigate large-scale transcript responses to a variety of developmental and environmental signals, ultimately improving our understanding of plant biology.

A sclerotia-forming fungus was isolated from a peanut field in eastern New Mexico, where Valencia peanut is grown. The isolated fungus was typified by its darkly pigmented mycelium when grown on culture media, with pigmentation influenced by media. The optimal temperature range for mycelial growth was 20 to 25°C. In pathogenicity tests, the fungus caused water-soaked and light tan lesions on stems at points of inoculation, and lesions progressed up the stems into petioles followed by collapse of leaves. White fluffy mycelium and sclerotia were present on inoculated plants. Based on the examination of morphological and cultural characteristics of sclerotia, apothecia, asci, and ascospores, the isolated fungus with darkly pigmented mycelium on culture media was identified as Sclerotinia sclerotiorum. This study is the first report of S. sclerotiorum on peanut in New Mexico.