Biologia reprodutiva de etnovariedades de mandioca

Silva, Rainério Meireles da; Bandel, Gerhard; Faraldo, Maria Inez Fernandes; Martins, Paulo Sodero

doi:10.1590/s0103-90162001000100016

Cited by 23 publications

(14 citation statements)

References 10 publications

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“…The number of pollen grains within each anther is considerably lower than those found in cereals or soybean (1 000 and 500 microspores, respectively). Pollination of Manihot species is mostly made by insects particularly honeybees (Da Silva et al 2001), whereas in the case of cereals, it is by wind. This explains the differences in the amount of pollen produced and their size.…”

Section: Resultsmentioning

confidence: 99%

Microsporogenesis and pollen formation in cassava

Wang

Lentini²,

Tabares³

et al. 2011

Biol. plant.

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This article describes the complete microsporogenesis and pollen formation in cassava (Manihot esculenta Crantz) at the various developmental stages (pollen mother cell, meiosis, tetrads, early free spore, mid uninucleate, late uninucleate, binucleate and mature pollen grain). Light microscopy, transmission electron microscopy and confocal laser scanning microscopy were used for the study. Floral bud size and other inflorescence characteristics were correlated with specific stages of the microspore development. This association allows a rapid selection of floral buds with similar microspore developmental stages, useful when a large number of homogeneous cells are needed for analysis and for in vitro induction of androgenesis. This article also compares methods for digestion the exine wall in microspores

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Section: Resultsmentioning

confidence: 99%

Microsporogenesis and pollen formation in cassava

Wang

Lentini²,

Tabares³

et al. 2011

Biol. plant.

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“…Once a plant matures, it flowers, is pollinated (the main agents of pollination are bees; Silva et al, 2001), its fruits grow, mature and burst, dispersing the seed. The germination ecology of manioc is thought to be pre-adapted to slash and burn systems, owing to its having evolved in transitional forest-savanna ecosystems predominant in Amazonia in the pre-Holocene period (Pujol et al, 2002).…”

Section: Selective Pressures On Manioc Landracesmentioning

confidence: 99%

Dark Earths and manioc cultivation in Central Amazonia: a window on pre-Columbian agricultural systems?

Fraser

Clement

2008

Bol. Mus. Para. Emílio Goeldi. Ciênc. hum.

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Many commentators highlight the fertility of Anthropogenic Dark Earths (ADE), emphasizing their potential for sustainable agriculture. Some scholars believe that terra mulata (the less fertile, more extensive form of ADE) was created by means of agricultural practices used by large settled populations of pre-Columbian farmers. But what was it that these Amerindian farmers were growing? Until recently, scholarly consensus held that manioc does not perform well on ADE. New research on the middle Madeira River is showing, however, that this consensus was premature. In this region, the most common crop in ADE fields is bitter manioc. Farmers there have various landraces of manioc that they believe yield particularly well on ADE, and logically plant more of these varieties on ADE. Aspects of the behaviour and perception of manioc cultivation among 52 farmers at the community of Barro Alto were measured quantitatively on four terra firme soil types (Terra Preta, Terra Mulata, Oxisols and Ultisols). These farmers plant different configurations of landraces in different soils, according to their perception of the suitability of particular landraces and their characteristics to certain soil types and successional processes. This, in turn, shapes selective pressures on these varieties, as new genetic material incorporated from volunteer seedlings is more likely to contain traits present in the most prevalent landrace(s) in each soil type. Owing to localized population pressure at Barro Alto, manioc is under more intensive cultivation systems, with shorter cropping periods (5-10 months) and shorter fallow periods (1-2 years). The outcome of these processes is different co-evolutionary dynamics on ADE as opposed to non-anthropogenic soils. Further anthropological study of manioc swiddening in one of the richest agricultural environments in Amazonia can fill a gap in the literature, thus opening an additional window on the pre-Columbian period.Keywords: Anthropogenic soils. Dark Earths. Agricultural Intensification. Manioc. Central Amazonia. Madeira River.Resumo: Muitos comentaristas realçam a fertilidade da Terra Preta de Índio (TPI), enfatizando seu potencial para uma agricultura sustentável. Alguns estudiosos acreditam que Terra Mulata (uma forma menos fértil, porém mais comum de TPI) foi criada por meio de práticas agrícolas usadas por grandes populações sedentárias na época pré-colombiana. Mas o que estes agricultores ameríndios cultivavam? Até recentemente, o consenso acadêmico era de que mandioca não se adaptava bem em TPI. Novas pesquisas no Médio Rio Madeira estão demostrando, porém, que este consenso era prematuro. Nesta região, a colheita mais comum em roças de TPI é mandioca amarga. Os agricultores têm diversas variedades crioulas (raças primitivas) de mandioca, que eles acreditam render especialmente bem em TPI e, logicamente, plantam mais destas variedades em TPI. Aspectos do comportamento e da percepção do cultivo de mandioca entre 52 agricultores da comunidade de Barro Alto foram observados quantita...

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“…O conhecimento da estrutura floral e da biologia reprodutiva numa cultura é básico para que o melhorista desenvolva técnicas de castração e polinização adequadas (Gomes et al, 2001;Silva et al, 2001). Segundo Damião Filho (1993), o rápido progresso alcançado no melhoramento das plantas cultivadas se deve aos estudos dos processos reprodutivos que ocorrem nas flores.…”

Section: (Recebido Em 3 De Julho De 2009 E Aprovado Em 25 De Janeiro unclassified

Aspectos da biologia reprodutiva de Jatropha curcas L

et al. 2010

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RESUMOO conhecimento da estrutura floral e da biologia reprodutiva numa cultura é básico para que o melhorista desenvolva técnicas de castração e polinização adequadas. Objetivando obter dados de biologia reprodutiva de pinhão manso, inflorescências emasculadas, foram observadas sem isolamento (controle positivo) e isoladas com tecido "nylon" tipo voal para posterior realização dos tratamentos de geitonogamia e xenogamia após a antese. Os tratamentos consistiram de controle positivo (flores não isoladas), e a partir das flores isoladas foram obtidos os demais tratamentos: controle negativo (sem polinização); xenogamia (receberam pólen de outra planta); geitonogamia 1 (receberam pólen da mesma inflorescência); geitonogamia 2 (receberam pólen de outra inflorescência da mesma planta). Os resultados indicam que a espécie não apresenta problemas de autoincompatibilidade, sendo os índices de fecundação bastante elevados e indiferentes estatisticamente em todos os tratamentos, com valores acima de 80%, exceto para o controle negativo em que as inflorescências foram isoladas e não polinizadas, resultando em ausência de fecundação e de frutos. Esse último resultado mostra a importância da visitação de insetos para a obtenção de sucesso no processo reprodutivo da espécie. As flores masculinas, doadoras de pólen, abrem no período da manhã, assim como as femininas. Sendo assim, embora haja visitação de insetos durante todo o dia, o processo de polinização ocorre no período matutino, em razão da quase total ausência de pólen no período vespertino.Termos para indexação: Jatropha curcas L., autofecundação, auto-incompatibilidade, polinização. ABSTRACTThe knowledge of the floral structure and reproductive biology are basic to a more successful for the development of techniques of castration and pollination in plant species. Aiming to obtain data about reproductive biology of physyc nut, free and enclosed inflorescences were observed without isolation (positive control) and isolation with nylon for posterior treatment of geitonogamy and xenogamy. So, treatments were positive control (free or unbagged inflorescences), and all other treatments obtained from isolated immature inflorescences enclosed within of fine nylon bags: negative control (without pollination), xenogamy (receiving pollen from another plant); geitonogamy 1 (received pollen from the same inflorescence), geitonogamy 2 (received pollen from another inflorescence of the same plant). The results indicate that the species does not present problems of self-incompatibility resulting in high fertilization and statistically indifferent in all treatments, presenting values above 80%, except for negative control in which the inflorescences were isolated and not pollinated resulting in lack of fertilization and fruit development. These results show the importance insects for success in the reproductive process of this species. The male flowers, pollen donors, opened in the morning, just like the female ones. Thus, although there is visitation of insects during all the day, t...

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Biologia reprodutiva de etnovariedades de mandioca

Cited by 23 publications

References 10 publications

Microsporogenesis and pollen formation in cassava

Microsporogenesis and pollen formation in cassava

Dark Earths and manioc cultivation in Central Amazonia: a window on pre-Columbian agricultural systems?

Aspectos da biologia reprodutiva de Jatropha curcas L

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