Luis Carlos da Silva Ramos

Variability for oil and fatty acid composition in castorbean varieties

Thirty-six castorbean varieties were surveyed for oil and fatty acid composition, in order to determine variability of these seed compounds. A large variability of seed oil percentage was observed, ranging from 39.6 to 59.5%. Concerning the fatty acids, little variability was observed for ricinoleic acid, which was the most abundant in the oil, ranging from 83.65 to 90.00%. The other fatty acids appeared in small concentrations and showed a small range: 0.87 to 2.35, 0.68 to 1.84, 2.96 to 5.64, 3.19 to 5.98, and 0.34 to 0.91%, for palmitic, stearic, oleic, linoleic, and linolenic acid, respectively. Non-significant correlations were observed between fatty acids and seed oil percentage. However, significant correlations were observed among fatty acid concentrations: positive and negative ones. These significant correlations could be associated with the biosynthetic pathways of the fatty acids, which are not fully elucidated. They suggest, however, that selection for a particular fatty acid will tend to increase those positively correlated, and decrease those negative ones. Selection and plant breeding techniques could then be applied to modify the oil content of the castorbean seeds, considering the variability observed. For the fatty acid composition, however, the variability was not large enough to make substantial changes in their concentrations by selection procedures. More varieties should be surveyed to find out if such variability is available.

Avaliação da superfície relativa do sistema radicular de cafeeiros

The root surface areas of 10 months old coffee plants (Coffea arabica L. cvs. Arabica and Catuai, C. canephora Pierre cv. Guarini, and C. arabica x C. canephora cv. Icatu) were evaluated by an adaptation of the WILD & VOIGHT (8) titration method. The root and shoot dry weight, stem diameter, shoot and root lengths were also measured. The plants were assigned in a randomized complete-block design with 5 blocks and 4 replications per plot. They were grown in polyethylene bags in a coffee nursery under 50% sun light. A greater root surface area, dry weight, stem diameter and shoot length was found in the cultivars Guarini. A high correlation between root surface area and root and shoot dry weights was observed for all studied coffee cultivars. The use of the titration method is suggested for measuring effects of physical, chemical and biological agents on root systems of coffee plants as well as other species.The root surface areas of 10 months old coffee plants (Coffea arabica L. cvs. Arabica and Catuai, C. canephora Pierre cv. Guarini, and C. arabica x C. canephora cv. Icatu) were evaluated by an adaptation of the WILD & VOIGHT (8) titration method. The root and shoot dry weight, stem diameter, shoot and root lengths were also measured. The plants were assigned in a randomized complete-block design with 5 blocks and 4 replications per plot. They were grown in polyethylene bags in a coffee nursery under 50% sun light. A greater root surface area, dry weight, stem diameter and shoot length was found in the cultivars Guarini. A high correlation between root surface area and root and shoot dry weights was observed for all studied coffee cultivars. The use of the titration method is suggested for measuring effects of physical, chemical and biological agents on root systems of coffee plants as well as other species.

SHOOT AND ROOT EVALUATIONS ON SEEDLINGS FROM Coffea GENOTYPES

Roots and shoots from seedlings of 29 coffee genotypes were studied to better characterize the entries from the Coffea germplasm bank of the Instituto Agronomico (IAC), Campinas, State of Sao Paulo, Brasil. The varieties were seeded in a randomized complete block design with 6 replications and 10 plants per plot. The characters evaluated were: plant (PL), shoot (SL) and root (RL) length; total plant (PDM), shoot (SDM), root (RDM) and lateral root (LRDM) dry matter. A lateral root index (LRI) and shoot root dry matter (SRDM = SDM/RDM) and length ratios; (SRL = SL/RL) were calculated. The dwarf varieties (Catuai, Icatu-caturra, Vila Sarchi, San Ramon, Vila Lobos, Sao Bernardo) presented higher LRDM and lower SDM than the normal size varieties such as Mundo Novo, Bourbon Vermelho, Arabica, Amarelo de Botucatu, Glaucia, etc. The varieties Macrodiscus, Icatu-caturra, Bourbon Amarelo, Vila Lobos and C. congensis showed higher root development related to shoot. The Arabica coffee standard variety showed intermediary root and shoot development. Genotypes of high yield background were higher in SL and SDM, while the dwarf types had only lower SL than the normal ones, but higher RL and dry matters. Seedlings from genotypes of known higher field drought tolerance had lower SL and RL, but higher RDM. Significant phenotypic and genotypic correlation coefficients were obtained, such the genotypes for PL and PDM (r = 0.64; P = 0.01), SL and SDM (r = 0.40; P = 0.05), SDM and LRDM (r = 0.52; P = 0.05), RDM and LRI (r = 0.68; P = 0.01), LRI and SRDM (r = 0.85; P = 0.01) and LRI and LRDM (r = 0.84; P = 0.01). High genotypic correlations suggest that selection directed to one character will directly affect the other. Conversely, low or non-significant correlations suggest independence of association, an indication that it would be possible to select two characteristics to diverse directions. Selection could be done towards different goals to change root and shoot measures (length and dry matter) because they were genotypically independent. However, care should be taken in controlling the environmental effects, because of significant positive phenotypic correlations.

Linhagens diaplóides de trigo: desempenho agronômico em dois locais do estado de São Paulo e tolerância à toxicidade de alumínio em laboratório

Twenty wheat genotypes (18 dihaploid lines and the IAC-24 and IAC-370 cultivars) were evaluated in experiments carried out under dryland and acid soil conditions in Capao Bonito and under sprinkler irrigation and limed soil conditions in Tatui in 2001-03 period. Grain yield, yield components, agronomic characteristics and disease resistance were evaluated. The genotypes were also evaluated for their tolerance to Al toxicity, in nutrient solutions, under laboratory conditions. IAC-24 and the dihaploid lines (L3, L4, L5, L8, L14, L15, L16, L17, L18, L19 e L20), in Capao Bonito, were superior for grain yield. In nutrient solutions, these were the most tolerant genotypes to aluminum toxicity. All genotypes exhibited semi-dwarf plant type. The dihaploid line L15 and L16, presented lodging resistance, IAC-370 longer spikes and higher number of grain per spike and per spikelet, L8 higher number of spikelets per spike and L6 and L7 the heavier grains. All evaluated genotypes were susceptible to leaf spot. The lines L4, L14, L15, L16, L17 and L18 originated from the cross R27/GHL121//KAL/BB/3/BUC/BUL/4/IAC-24 showed resistance to leaf rust. The higher grain yield genotypes, under dryland and acid soil conditions, were associated to taller semi-dwarf plants with tolerance to aluminum toxicity. Under sprinkler irrigation and limed soil conditions the highest yielding genotypes were not associated to either semi-dwarf plants or those tolerant to aluminum toxicity.

Comportamento de linhagens diaplóides de trigo em dois locais do Estado de São Paulo

Twenty wheat genotypes (18 dihaploid lines and the IAC-24 and IAC-289 cultivars) were evaluated in experiments carried out under dryland and acid soil conditions in Capao Bonito (1997-99), and under sprinkler irrigation and acid soil conditions with lime application in Tatui (1997-2000). Grain yield, yield components, agronomic characteristics and disease resistance were analyzed. In addition, the genotypes were evaluated for their tolerance to Al toxicity, in nutrient solutions, at laboratory conditions. The dihaploid lines 10 and 11 and the cultivar IAC-24, in Capao Bonito, and the cultivar IAC-24 and the dihaploid line 19, in Tatui, were superior for grain yield. The dihaploid line 5 presented lodging resistance, the line 20 showed short stature and early plants to mature, and the cultivar IAC-289 exhibited higher number of spikelets per spike and heavier grains. All evaluated genotypes were susceptible to leaf spot. In relation to leaf rust, all lines were resistant, except the line 20 which was moderately resistant. The cultivar IAC-24 and all evaluated dihaploid lines were tolerant to aluminum toxicity. The higher grain yield genotypes, under dryland and acid soil conditions, were associated to tall plants, with long spikes, with high number of grains per spike and per spikelet and with tolerance to aluminum. Under sprinkler irrigation and acid soil conditions with lime application the most productive genotypes were associated to tall plants (semidwarf type) with heavy grains, and presenting no correlation with tolerance to aluminum.

Comportamento de três cultivares de soja em diversos níveis de manganês em solução nutritiva

Three soybean cultivars were grown in nutrient solution to investigate their response to Mn using 0, 3, 6, and 10 ppm of Mn, as MnCl2.5H2O The results showed that 3 ppm was beneficial in increasing the dry matter yield of the above ground parts of the cultivars Davis, Santa Rosa and Biloxi. At 6 and 10 ppm of Mn, Davis and Santa Rosa were reduced considerably, and Biloxi showed reduction of dry matter only at the 10 ppm level. The weight of dry matter of leaves, or the above ground parts, height of the plant and the weight of the roots could be used as parameters to evaluate tolerance to Mn. On the other hand, root lenght was not a good indicator.

Seed-oil content of glanded and glandless cottons

Twelve cotton strains, six glanded and six glandless, with different seed-oil contents, were mated in a full diallel system. All genotypes were evaluated for seed-oil percentage (SO), seed index (SI, mg/seed) and seed-oil index (SOI, mg/seed) to obtain information on the inheritance of these traits and to assess the significance of maternal and reciprocal effects. Data generated from the diallel mating system were additionally divided into two full diallels, glanded and glandless, of six parents each and evaluated by combining ability and diallel analyses.The results indicated that maternal effects were not statistically significant for any trait, but reciprocal effects were significant for SI and SOI. Additive effects, or general combining ability (GCA), were highly significant in both analyses. Deviations from additivity, or specific combining ability (SCA), were significant for SI and SOI, and for SO in the glanded diallel. Deviations from additivity were not homogeneous over all the genotypes. Only the additive parameter of the genetic analysis for glandless SO was significant. This result indicated that additivity was greater in crosses involving glandless genotypes. Heritability of 0.53 based on GCA values was obtained for SO, which indicated that selection procedures could be applied successfully to change the oil content of cottonseed.The highest SO parent was glandless, and the glandless genotypic arrays averaged more SO than glanded arrays, indicating that glandless genotypes could be preferred over glanded in breeding for this trait.

Development of seedlings of four coffee cultivars

) Com bolsa de suplementacao do CNPq. P) MONACO. L. C; SCALI. M. H.; CARVALHO. A. & FAZUOLI. L. C. Variabilidade no sistema radicular de genotipos de cafe. Ciencia e Cultura (Resumos), Sao Paulo, 25:247, 1973. (*) LEON, J. & UMANA, R. Diferencias varietales en ei sistema radical dei cafe. Cafe IICA, Turrialba, 3(11):130-133, 1961. (

Effect of 6-BA on nodal explant bud sproutings of Coffea arabica cv. Mundo Novo

O cafeeiro pode ser micropropagado via brotacao de gemas laterais, aplicando o regulador de crescimento 6-benzilaminopurina (6-BA). Entretanto, a literatura apresenta ampla variacao da dose empregada, desde 0.5 a 88.8 µM L-1. Assim, este estudo visou otimizar doses para explantes nodais do cafeeiro C. arabica cv Mundo Novo. Explantes nodais, obtidos de plântulas cultivadas in vitro, foram inoculados em meio MS geleificado, com adicao de diferentes concentracoes de 6-BA. Foram feitos dois experimentos: no primeiro, 6-BA foi usado nas doses de 0, 5, 10, 25, 50 e 100 µM L-1 e avaliado aos 43 e 123 dias; no segundo, 10, 20 e 30 µM L-1, avaliado aos 65 e 100 dias apos a inoculacao dos explantes. Os tratamentos com 6-BA induziram a multibrotacao dos explantes nodais, e os resultados foram mais bem caracterizados aos cem dias. Os explantes nodais tratados formaram multibrotacoes que tambem atingiram maior altura; todavia, o efeito de 6-BA nas concentracoes entre 5 a 25 µM L-1 foi semelhante ao das doses mais elevadas, 50 e 100 µM L-1. As doses de 5 a 25 µM L-1 de 6-BA induziram a brotacao de 2,9 a 6,0 gemas por no, atingindo de 1,3 a 1,5 cm, enquanto os tratamentos de 50 a 100 µM L-1 formaram 3,0 a 4,9 gemas por no e as suas brotacoes atingiram cerca de 0,8 cm de altura. Observou-se neste estudo que a multibrotacao de explantes nodais de C. arabica cv Mundo Novo pode ser induzida por concentracoes menores de 6-BA, entre 10 a 30 µM L-1, diminuindo os riscos de variacao somaclonal devido as altas concentracoes de hormonio.

Root surface area of coffee plants by the titration method

The root surface areas of 10 months old coffee plants (Coffea arabica L. cvs. Arabica and Catuai, C. canephora Pierre cv. Guarini, and C. arabica x C. canephora cv. Icatu) were evaluated by an adaptation of the WILD & VOIGHT (8) titration method. The root and shoot dry weight, stem diameter, shoot and root lengths were also measured. The plants were assigned in a randomized complete-block design with 5 blocks and 4 replications per plot. They were grown in polyethylene bags in a coffee nursery under 50% sun light. A greater root surface area, dry weight, stem diameter and shoot length was found in the cultivars Guarini. A high correlation between root surface area and root and shoot dry weights was observed for all studied coffee cultivars. The use of the titration method is suggested for measuring effects of physical, chemical and biological agents on root systems of coffee plants as well as other species.The root surface areas of 10 months old coffee plants (Coffea arabica L. cvs. Arabica and Catuai, C. canephora Pierre cv. Guarini, and C. arabica x C. canephora cv. Icatu) were evaluated by an adaptation of the WILD & VOIGHT (8) titration method. The root and shoot dry weight, stem diameter, shoot and root lengths were also measured. The plants were assigned in a randomized complete-block design with 5 blocks and 4 replications per plot. They were grown in polyethylene bags in a coffee nursery under 50% sun light. A greater root surface area, dry weight, stem diameter and shoot length was found in the cultivars Guarini. A high correlation between root surface area and root and shoot dry weights was observed for all studied coffee cultivars. The use of the titration method is suggested for measuring effects of physical, chemical and biological agents on root systems of coffee plants as well as other species.