Received by A.J. van WijnenKeywords: myo-inositol phosphate synthase (MIPS) Sucrose synthase (Sus) Seed developmentThe aim of this review is to highlight the role of myo-inositol phosphate synthase (MIPS), which catalyses the first step in inositol biosynthesis and of sucrose synthase (Sus), an enzyme involved in UDP-glucose formation, the principal nucleoside diphosphate in the sucrose cleavage reaction and in trehalose biosynthesis. These two enzymes are involved in various physiological processes including seed growth and resistance to biotic and abiotic stresses. The study of mutated MIPS and Sus genes in some crops, such as soybean and cotton, has shown that these two proteins are directly involved in embryogenesis. They exhibit several isoforms that are essential for normal seed development. The possible role of both genes in seed development is discussed in this review.

RESUMOEste artigo pretende levantar evidências de como as atuais práticas de ação coletiva, no contexto da cooperação empresarial, poderão complementar ou até mesmo questionar as perspectivas dominantes no campo da estratégia organizacional. O estudo, fundamentado em uma visão relacional, revisita três abordagens clássicas nas pesquisas sobre o tema: estrutura da indústria, visão baseada em recursos e custos de transação. O que instiga a presente pesquisa é a possibilidade de explorar uma aparente dissonância entre alguns dos postulados dessas perspectivas frente às práticas de gestão que se utilizam de ações coletivas como base para o alcance de competitividade organizacional. Para lançar luz sobre essas especulações empíricas, objetivou-se aprofundar o estudo de campo junto às redes de cooperação empresarial localizadas no Estado do Rio Grande do Sul. Tal contexto empírico é resultado de uma política pública específica que promoveu a criação de mais de 200 redes de pequenas e médias empresas. Para a coleta de dados, foram realizadas 60 entrevistas em profundidade em 12 redes de cooperação. As evidências encontradas permitiram formular indagações para as perspectivas dominantes no campo da estratégia. A primeira delas questiona a abordagem individualista da perspectiva da estrutura da indústria, demonstrando que é possível atingir uma posição superior de competitividade em uma indústria a partir da colaboração, inclusive com os concorrentes. A segunda evidência, a visão relacional da estratégia, complementa a visão baseada em recursos, demonstrando que os ativos gerados coletivamente, em vez daqueles mantidos exclusivamente pela empresa individual, podem igualmente sustentar uma estratégia para competir no mercado. Por fim, a terceira evidência encontrada também indica que a redução dos custos de transação poderá ocorrer por meio do estreitamento das relações no contexto de uma rede, as quais minimizam as exigências contratuais e aumentam a confiança entre as empresas envolvidas.Palavras-chave: cooperação, estratégia, competitividade, pequenas empresas, redes. ABSTRACTThe purpose of this article is to debate evidence of how collective action in business cooperation networks can complement or even question the dominant perspectives of organization strategy. The present study is supported by the emerging relational view of strategy, rather than by its traditional individual view, and it revisits three leading approaches about strategy: industry structure, resource-based view and transaction costs. The motivator for this investigation is ALSONES BALESTRINabalestrin@unisinos.br

Results are presented of studies conducted in the Central Valley of Costa Rica to support the in situ conservation of wild Lima bean, Phaseolus lunatus, prone to extinction as a result of growing urbanization and changes in agricultural and land use practices. To achieve the conservation objective, several investigations were conducted in the following areas: (i) ecogeography and metapopulation dynamics; (ii) population demography and phenology; (iii) floral biology and gene flow; (iv) genetic structure of populations using morphological, biochemical and molecular markers; and (v) in situ conservation methodologies. These investigations were made under the project 'Studies on breeding systems: the case of a short-living perennial, alternatively outbreeder-inbreeder species (P. lunatus) and its consequences for germplasm conservation', which ran in 2- to 4-year phases from 1992 to 2000 with funding from Belgium's Directorate General for Development Cooperation. It was a collaboration among three partners: International Plant Genetic Resources Institute's Regional Office for the Americas in Cali, Colombia, the Escuela de Biología of the Universidad de Costa Rica and the Unité de Phytotechnie tropicale et d'Horticulture of Gembloux Agricultural University, Belgium. Recommendations are given.

In this paper, the causes of early embryo abortion in the reciprocal crosses between Phaseolus vulgaris L. (a cultivar) and Phaseolus coccineus L. (a wild form) were studied. Methacrylate resin sections, 3-5 lm thick, of 3 to 14 day-old seeds were used to examine the embryo developmental stages and the state of seed tissue. It was observed that, embryos aborted at different developmental stages (globular to early cotyledon) depending on the maternal parent. The use of P. coccineus cytoplasm resulted in a higher number of abortion than in reciprocal crosses. Many of them took place between 5 and 6 days after pollination (DAP). Histological analyses permitted to observe that the embryo development was slower in the cross between P. coccineus and P. vulgaris, compared to parental seeds. It would be related to a deficient endosperm development in reciprocal crosses and, in some extent, hypertrophy of the suspensor might be the main cause of early embryo abortion. Then, it would be practical to overcome this incompatibility by rescuing the embryo at the globular stage of development.