Analysis of expressed sequence tags generated from full-length enriched cDNA libraries of melon

Abstract Background Melon (Cucumis melo), an economically important vegetable crop, belongs to the Cucurbitaceae family which includes several other important crops such as watermelon, cucumber, and pumpkin. It has served as a model system for sex determination and vascular biology studies. However, genomic resources currently available for melon are limited. Result We constructed eleven full-length enriched and four standard cDNA libraries from fruits, flowers, leaves, roots, cotyledons, and calluses of four different melon genotypes, and generated 71,577 and 22,179 ESTs from full-length enriched and standard cDNA libraries, respectively. These ESTs, together with ~35,000 ESTs available in public domains, were assembled into 24,444 unigenes, which were extensively annotated by comparing their sequences to different protein and functional domain databases, assigning them Gene Ontology (GO) terms, and mapping them onto metabolic pathways. Comparative analysis of melon unigenes and other plant genomes revealed that 75% to 85% of melon unigenes had homologs in other dicot plants, while approximately 70% had homologs in monocot plants. The analysis also identified 6,972 gene families that were conserved across dicot and monocot plants, and 181, 1,192, and 220 gene families specific to fleshy fruit-bearing plants, the Cucurbitaceae family, and melon, respectively. Digital expression analysis identified a total of 175 tissue-specific genes, which provides a valuable gene sequence resource for future genomics and functional studies. Furthermore, we identified 4,068 simple sequence repeats (SSRs) and 3,073 single nucleotide polymorphisms (SNPs) in the melon EST collection. Finally, we obtained a total of 1,382 melon full-length transcripts through the analysis of full-length enriched cDNA clones that were sequenced from both ends. Analysis of these full-length transcripts indicated that sizes of melon 5' and 3' UTRs were similar to those of tomato, but longer than many other dicot plants. Codon usages of melon full-length transcripts were largely similar to those of Arabidopsis coding sequences. Conclusion The collection of melon ESTs generated from full-length enriched and standard cDNA libraries is expected to play significant roles in annotating the melon genome. The ESTs and associated analysis results will be useful resources for gene discovery, functional analysis, marker-assisted breeding of melon and closely related species, comparative genomic studies and for gaining insights into gene expression patterns.This work was supported by Research Grant Award No. IS-4223-09C from BARD, the United States-Israel Binational Agricultural Research and Development Fund, and by SNC Laboratoire ASL, de Ruiter Seeds B.V., Enza Zaden B.V., Gautier Semences S.A., Nunhems B.V., Rijk Zwaan B.V., Sakata Seed Inc, Semillas Fitó S.A., Seminis Vegetable Seeds Inc, Syngenta Seeds B.V., Takii and Company Ltd, Vilmorin and Cie S.A. and Zeraim Gedera Ltd (all of them as part of the support to ICuGI). CC was supported by CNRS ERL 8196.Peer Reviewe

Micropropagation of walnut trees (Juglans regia L) and response to arbuscular mycorrhizal inoculation

Juglans regia clones were micropropagated through the establishment of in vitro shoot-tip cultures and induction of adventitious roots. Shoot proliferation of juvenile J regia material was higher than with clones established from adult trees. Genotype and juvenility of the plant material were determinant factors of the in vitro rooting ability. Rooting of adult J regia clones was improved after rejuvenation by subsequent subcultures. The sucrose concentration in the root elongation medium affected the formation of secondary roots per rooted shoot and the acclimatization of plants. Mycorrhizal inoculation of micropropagated walnut trees improved post-acclimatization growth in greenhouse conditions. Inoculation with the arbuscular mycorrhizal fungi Glomus mosseae or G intraradices significantly improved plant survival when transferred to nursery.Micropropagation du noyer (Juglans regia L) et effet de l'inoculation avec des champignons mycorhizogènes à arbuscules. Des clones de noyer, Juglans regia, ont été micropropagés via l'établissement de cultures in vitro d'extrémités de tiges et l'induction de racines adventives. La prolifération des tiges a été plus grande pour les clones juvéniles que pour les clones établis à partir d'arbres adultes. L'aptitude d'enracinement in vitro a varié avec le contexte génétique et le stade, juvénile ou adulte, du matériel de base. Le taux d'enracinement de clones adultes de J regia a augmenté après rajeunissement du matériel au moyen de subcultures successives. La concentration de sucrose dans le milieu d'élongation des racines a eu un effet sur le nombre de racines formées et sur le sevrage des plantes. La mycorhization des noyers micropropagés a amélioré la croissance des plantes en serre. L'inoculation avec les deux champignons mycorhizogènes essayés : Glomus mosseae et Glomus intraradices a augmenté le taux de survie des noyers lors de leur transplantation en pépinière

Selection for new pear rootstocks : in vitro screening and field evaluation for tolerance to iron chlorosis

International audienc

Breeding of pear rootstocks. Firt evaluation of new interspecific rootstocks for tolerance to lime-induced chlorosis and induced vigour under field conditions

International audienc

Meio de cultura, concentração de AIB e tempo de cultivo no enraizamento in vitro de amoreira-preta e framboeseira Culture environment, IBA concentration and cultivation time on in vitro rooting of blackberry and raspberry

A propagação da amoreira-preta e da framboeseira dá-se principalmente por meio de estacas de raiz e mesmo de hastes novas, contudo, já é crescente o interesse pelo uso da micropropagação como um método alternativo de propagação . O enraizamento é uma das etapas mais difícieis, onde a definição do meio de cultivo, da concentração ótima de AIB para o enraizamento, constitui um passo importante, por isso objetivou-se com este experimento determinar o melhor meio de cultivo, melhor tipo de cultivo e a melhor concentração de AIB no meio de cultura para o enraizamento in vitro da amoreira-preta 'Xavante' e de framboeseira 'Batum' e 'Heritage'. O material vegetal utilizado foram microestacas apicais com duas folhas, com cerca de 1 cm de comprimento, oriundas do cultivo in vitro. Os fatores estudados foram o tipo de meio de cultura MS e WPM - Wood Plant Media, a concentração de AIB no meio de cultura e o tempo de cultivo das microestacas em meio com AIB. O meio WPM, em concentrações baixas, menores de 3 µM de AIB, induziram maiores médias de enraizamento e comprimento. Concentrações altas de AIB induziram a formação de calo, para amoreira-preta, 'Xavante'. Para a framboeseira o meio WPM, com menores concentrações de AIB (0 e 3 µM), mostrou as melhores médias no número de raízes, comprimento de raízes e pequena intensidade de calo; com as maiores concentrações de AIB, ocorreu maior aparecimento de calo.<br>The propagation of blackberry and raspberry occur mainly through root cutting and even of softwoods stem; however, it is already increasing the interest for the use of the micropropagation as an alternative technique of vegetative propagation of fruit plants, since the rooting is one of the most difficult stages, in which the definition of both the culture environment and the best concentration of AIB for the rooting, is an important stage. For that purpose, the aim of this research was to determine the best cultivation type and the best concentration of IBA in the culture environment for the in vitro rooting of the blackberry 'Xavante' and the raspberry 'Batum' and 'Heritage'. The vegetable material used was atex microcutting with two leaves, measuring about 1 cm of length, originated from the in vitro cultivation. The studied factors were the kinds of culture (MS and WPM), the IBA concentration in the culture environment and the time of cultivation of the microcutting in an environment with IBA. The WPM environment, in low concentrations, less than 3 µM of IBA, together with T1, induced larger rooting averages and length. High concentrations of AIB induced the callus formation for blackberry 'Xavante'. For raspberry, using WPM environment with smaller concentrations of AIB (0 and 3 , µM), it was shown the best average in the number of roots, length of roots and small callus intensity, with the largest concentrations of IBA it happened larger callus emergence