Resumo O coqueiro (Cocos nucifera L.) é uma das mais importantes espécies tropicais utilizadas pelo homem, conhecida como “árvore da vida”. Nas últimas décadas, com a expansão das áreas de cultivo, limitações como a ocorrência de pragas, uniformidade de culturas, adaptação a diferentes ecossistemas e outras têm afetado a produção e a longevidade dos plantios. Esta revisão descreverá os principais avanços nas técnicas de propagação do coqueiro, convencionalmente, por sementes e por meio de técnicas de cultura de tecidos de plantas a partir de meados do século XX, bem como aspectos fitossanitários que devem ser considerados para mitigar a disseminação de pragas e doenças.

Abstract Coconut palm (Cocos nucifera L.) is one of the most important tropical species used by man, known as “tree of life”. In recent decades, with the expansion of coconut growing areas, limitations such as the occurrence of pests, uniformity of crops, adaptation to different ecosystems and others have affected the production and longevity of coconut trees. This review describes the major advances in propagation techniques of coconut palm, conventionally, by seeds and through plant tissue culture techniques from the mid-twentieth century onwards, as well as phytosanitary aspects that should be considered to mitigate the spread of pests and diseases.

ABSTRACT The preservation of banana genetic material is usually performed through seedlings. However, most banana cultivars do not produce seed and are propagated vegetatively. Therefore, cryopreservation is a feasible technique that allows the preservation of banana genotypes indefinitely. For the success of cryopreservation protocols, the selection of cryoprotectants and pre-freezing techniques are important factor. Therefore, the objective of this study was to verify the effects of different cryoprotectants with and without 1% phloroglucinol and pre-cooling periods on the development of a protocol for cryopreservation of in vitro rhizomes ofMusa accuminata(AAA) cv Grand Naine banana. The addition of 1% phloroglucinol to the cryoprotective solutions, such as PVS2 enhanced recovery of cryopreserved banana rhizomes. In addition, pre-cooling of explants in ice for 3 hours in PVS2 + 1% of phloroglucinol allowed efficient cryopreservation of banana rhizomes, followed by successful recovery and regeneration of in vitro shoots of banana cv Grand Naine.

ABSTRACT Jatropha is a potential oilseed crop, which requires mitigating factors such as the low genetic variability of the species. The solution runs through the research of Brazilian germplasm. Attention should be given to the germplasm of jatropha the north of Minas Gerais, because this is the oldest national collection and because this region may be a regions of jatropha diversity due to selection pressure arising from environmental adversities. Therefore, the objective of this study was to investigate the genetic diversity of 48 accessions of collection from Empresa de Pesquisa Agropecuária de Minas Gerais (EPAMIG), using SSR and ISSR markers. The results showed low genetic diversity, but some individuals stood out as J. mollissima (48), J. podagrica (47), Mexican accessions (42, 43, 44 and 45) and some national accessions (28, 29, 41 and 46). Therefore, aiming to increase the genetic variability and improve the effectiveness of jatropha breeding programs, it is suggested to explore such as parental accessions to generate commercial hybrids. This fact implies the possibility to support future production of jatropha, since this culture may be an important source of income, especially for small farmers living in semiarid regions of Brazil.

The present study investigated the germination and vigor of Caesalpinia echinata (Brazilwood) seeds stored at negative temperatures. Recently harvested seeds were cryopreserved at -18º or -196ºC and periodically evaluated for germination, seed vigor and carbohydrate composition. The temperatures did not influence the germination percentages or vigor. The germination percentage decreased from 88% in recently harvested seeds to 60% after 730 days of storage. The different temperature and storage times tested did not affect the vigor seed germination as indicated by the measures of plant growth and survival. The different temperatures used did not cause changes in the carbohydrate composition. The tegument cell walls were rich in lignin, arabinose and xylose. The cytoplasm of the cotyledons and embryos had high levels of glucose, fructose, and sucrose. The cryopreservation technique here presented was effective in the conservation of Brazilwood seeds for the medium term.

The ecophysiological behavior of brazilwood (Caesalpinia echinata Lam.) plants was evaluated as affected by light quantity and quality. Nine-month-old plants were cultivated under 0%, 50%, and 80% artificial shading, and natural shading imposed by a closed canopy for a period of 392 days. At the end of that period growth parameters were measured, including relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf mass (SLM) and root:shoot ratio (R:S). Higher leaf area, dry mass and RGR were obtained under 50% artificial shade. Under full sunlight (0% shade), growth was satisfactory showing higher R:S and SLM. Growth was inhibited under 80% artificial and natural shading indicating that C. echinata is not pioneer-succession or climax specie. Simulating a gap, plants cultivated under artificial shade (50%) were transferred to full sunlight for an interval of 192 h, during which net photosynthesis (A), transpiration (E), stomatic conductance (gs), deficit of pressure vapor (VPDleaf-to-air) and the efficiency quantum potential of photosystem II (Fv/Fm) were analyzed. Plants transferred to full sunlight presented severe burning and abscission of the leaflets, as well as inhibition of A and of the photochemical efficiency of PSII (Fv/Fm). This observation associated with the reduced growth under full sunlight and better performance under moderate shade suggests characteristics of intermediate species.