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Registro Completo |
Biblioteca(s): |
Embrapa Cerrados. |
Data corrente: |
23/11/1999 |
Data da última atualização: |
23/11/1999 |
Autoria: |
COSTA, S. P. |
Título: |
Physiological and anatomical factors enfluencing the pattern of carbohydrate accumulation in senescent and nonsescent sorghum (Sorghum bicolor (L.) Moench) plants. |
Ano de publicação: |
1985 |
Fonte/Imprenta: |
[College Station]: Texas A&M University, 1985. |
Páginas: |
147p. |
Idioma: |
Inglês |
Notas: |
Doctors of Philosophy Thesis. |
Conteúdo: |
Two sorghum cultivars, ATx378 x RTx430[(34), higher stem carbohydrates and slower rate of senescencel] and ATx378 x RTx7000 [(37), lower stem carbohydrates and more rapid rate of senescencel] were utilized in a stydy of factors to determine possible anatomical and physiological differences. Plant spacings of 10 or 40 cm four within the rows, were used. Evaluations were performed at four selected matutiry stages: (PB), 15 days post anthesis (PA), layer (PBL). Cultivar 34 had approximateley 45% of the bundle-sheath cell volume filled with chloroplasts, 2 - 3 - 3 mesophyll cells between veins and a shorter distance between veins. By contrast, cultivar 37 contained only 19% of the bundle-sheath cell volume filled with chloroplasts, 3 - 4 mespphyll cells between veins and a larger distance between veins. Stems of closer spaced plants contained more but smaller vascular bundles than wider spaced ones. Phoem vessels of cultivar 34 coveres 23% of the total vascular bundle area, whereas only 18% was covered for 37. Cultivar 34 produced the highest carbon dioxide assimilation rates. PEP carboxylase enzyme activity, measured in the crude extract of the flag leaf, and the assimilation rates, descresead in a stepwise trend as plant maturity progresses. Cultivar 34 produced significantly higher stem nonstructural carbohydrates (NSC) for all fractions determined. Closes spaced plants contained significantly higher levels of sucrose and total NSC. The lowest concentration for all carbohydrate franctions, except glicose, generally ocurred at PA, which coincided with maximum panicle growth and kernel filling. After completion of kernel filling, carbohydrates were again accumulated in the stem. Starch was present in higher levels at the earlier, decresead a PA and incresead again at later stages, but at higher concentrations for the slower senesing than for the faster senescing cultivar. Higher carbohydrate accumulation of the cultivar 34 was evidently enhanced by the leaf characteristics. This is indicated by a larger volume of bundle-sheath cell chloroplasts, higher density of mesophyll chloroplasts, and a shorter distance between veins. This, plus a larger area of phoem vessels in the stem vascular bundles should result in a more efficient transport system. MenosTwo sorghum cultivars, ATx378 x RTx430[(34), higher stem carbohydrates and slower rate of senescencel] and ATx378 x RTx7000 [(37), lower stem carbohydrates and more rapid rate of senescencel] were utilized in a stydy of factors to determine possible anatomical and physiological differences. Plant spacings of 10 or 40 cm four within the rows, were used. Evaluations were performed at four selected matutiry stages: (PB), 15 days post anthesis (PA), layer (PBL). Cultivar 34 had approximateley 45% of the bundle-sheath cell volume filled with chloroplasts, 2 - 3 - 3 mesophyll cells between veins and a shorter distance between veins. By contrast, cultivar 37 contained only 19% of the bundle-sheath cell volume filled with chloroplasts, 3 - 4 mespphyll cells between veins and a larger distance between veins. Stems of closer spaced plants contained more but smaller vascular bundles than wider spaced ones. Phoem vessels of cultivar 34 coveres 23% of the total vascular bundle area, whereas only 18% was covered for 37. Cultivar 34 produced the highest carbon dioxide assimilation rates. PEP carboxylase enzyme activity, measured in the crude extract of the flag leaf, and the assimilation rates, descresead in a stepwise trend as plant maturity progresses. Cultivar 34 produced significantly higher stem nonstructural carbohydrates (NSC) for all fractions determined. Closes spaced plants contained significantly higher levels of sucrose and total NSC. The lowest concentration for all carbohydr... Mostrar Tudo |
Palavras-Chave: |
Carbohydrate; Senescence. |
Thesagro: |
Anatomia Vegetal; Carboidrato; Fisiologia; Senescência; Sorghum Bicolor; Sorgo. |
Thesaurus Nal: |
plant anatomy; plant physiology. |
Categoria do assunto: |
-- |
Marc: |
LEADER 03050nam a2200253 a 4500 001 1559430 005 1999-11-23 008 1985 bl uuuu m 00u1 u #d 100 1 $aCOSTA, S. P. 245 $aPhysiological and anatomical factors enfluencing the pattern of carbohydrate accumulation in senescent and nonsescent sorghum (Sorghum bicolor (L.) Moench) plants. 260 $a[College Station]: Texas A&M University$c1985 300 $a147p. 500 $aDoctors of Philosophy Thesis. 520 $aTwo sorghum cultivars, ATx378 x RTx430[(34), higher stem carbohydrates and slower rate of senescencel] and ATx378 x RTx7000 [(37), lower stem carbohydrates and more rapid rate of senescencel] were utilized in a stydy of factors to determine possible anatomical and physiological differences. Plant spacings of 10 or 40 cm four within the rows, were used. Evaluations were performed at four selected matutiry stages: (PB), 15 days post anthesis (PA), layer (PBL). Cultivar 34 had approximateley 45% of the bundle-sheath cell volume filled with chloroplasts, 2 - 3 - 3 mesophyll cells between veins and a shorter distance between veins. By contrast, cultivar 37 contained only 19% of the bundle-sheath cell volume filled with chloroplasts, 3 - 4 mespphyll cells between veins and a larger distance between veins. Stems of closer spaced plants contained more but smaller vascular bundles than wider spaced ones. Phoem vessels of cultivar 34 coveres 23% of the total vascular bundle area, whereas only 18% was covered for 37. Cultivar 34 produced the highest carbon dioxide assimilation rates. PEP carboxylase enzyme activity, measured in the crude extract of the flag leaf, and the assimilation rates, descresead in a stepwise trend as plant maturity progresses. Cultivar 34 produced significantly higher stem nonstructural carbohydrates (NSC) for all fractions determined. Closes spaced plants contained significantly higher levels of sucrose and total NSC. The lowest concentration for all carbohydrate franctions, except glicose, generally ocurred at PA, which coincided with maximum panicle growth and kernel filling. After completion of kernel filling, carbohydrates were again accumulated in the stem. Starch was present in higher levels at the earlier, decresead a PA and incresead again at later stages, but at higher concentrations for the slower senesing than for the faster senescing cultivar. Higher carbohydrate accumulation of the cultivar 34 was evidently enhanced by the leaf characteristics. This is indicated by a larger volume of bundle-sheath cell chloroplasts, higher density of mesophyll chloroplasts, and a shorter distance between veins. This, plus a larger area of phoem vessels in the stem vascular bundles should result in a more efficient transport system. 650 $aplant anatomy 650 $aplant physiology 650 $aAnatomia Vegetal 650 $aCarboidrato 650 $aFisiologia 650 $aSenescência 650 $aSorghum Bicolor 650 $aSorgo 653 $aCarbohydrate 653 $aSenescence
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3. |  | CUNHA, A. O.; ARAGÃO, W. M.; MILANI, M.; PAULA NETO, V. de; ALMEIDA, A. C. O. de. Comportamento de cultivares de mamoneira em duas regiões ecogeográficas de Sergipe. In: CONGRESSO BRASILEIRO DE MELHORAMENTO DE PLANTAS, 4., 2007, São Lourenço, MG, 2007.Tipo: Artigo em Anais de Congresso / Nota Técnica | Circulação/Nível: -- - -- |
Biblioteca(s): Embrapa Algodão. |
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4. |  | CUNHA, A. O. C.; ARAGÃO, W. M.; MILANI, M.; PAULA NETO, V. de; ALMEIDA, A. C. O. de. Comportamento de cultivares de mamoneira no Semi-Árido sergipano. In: CONGRESSO BRASILEIRO DE MELHORAMENTO DE PLANTAS, 4., 2007, São Lourenço, MG, 2007.Tipo: Artigo em Anais de Congresso / Nota Técnica | Circulação/Nível: -- - -- |
Biblioteca(s): Embrapa Algodão. |
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