Physic Nut Genotypes Research Articles

Elucidating the Etiology and Temporal Progress of Rust on Physic Nut Genotypes and Their Relationship with Environmental Conditions in Ecuador

Physic nut (Jatropha curcas L.) has emerged as a promising fruit crop in Ecuador, but the recent identification of rust poses a potential threat to its productive development. This study focused on elucidating the morphological aspects of the basidiomycete and assessing rust intensity across different canopy levels of physic nut hybrids and genotypes under field and semi-controlled conditions in Manabí, Ecuador. For the first time, this study confirms that Phakopsora arthuriana should be responsible for rust on physic nut in Ecuador based on the characteristics of the fungal structures. Rust incidence was 100% across all canopy layers, with the lower and middle canopies exhibiting higher severity and lesion numbers than the upper canopy. Using the Weibull nonlinear distribution model, we epidemiologically modeled disease progression, revealing that hybrid JAT 001100 displayed the highest temporal progress, recording 15% severity and an area under the disease progression curve of 3228.9 units. Promising genotypes CP-041 and CP-052 demonstrated lower rust intensity. Environmental parameters, including dew point, temperature, precipitation, and relative humidity, were correlated with rust severity and lesion numbers. In greenhouse assays, hybrid JAT 001165 showed higher severity, whereas JAT 001103 and JAT 001164 had more lesions than other genotypes. In contrast, promising genotypes CP-041 and CP-052 consistently exhibited lower rust intensity in both field and greenhouse environments. This study demonstrated that P. arthuriana could be epidemiologically modeled with the Weibull model, providing crucial insights into the dynamic interplay between rust infection and physic nut hybrids and genotypes under diverse conditions in the Manabí region of Ecuador.

Mixed models identify physic nut genotypes adapted to environments with different phosphorus availability.

The aim of this study was to screen physic nut (Jatropha curcas) genotypes that differ in their phosphorous (P) use, using mixed models. The experiment was conducted in a greenhouse located in the experimental area of the Centro de Ciências Agrárias of the Universidade Federal do Espírito Santo, in Alegre, ES, Brazil. The experiment was arranged in a randomized block design, using a 10 x 3-factorial scheme, including ten physic nut genotypes and two environments that differed in their levels of soil P availability (10 and 60 mg/dm3), each with four replications. After 100 days of cultivation, we evaluated the plant height, stem diameter, root volume, root dry matter, aerial part dry matter, total dry matter, as well as the efficiency of absorption, and use. The parameters were estimated for combined selection while considering the studied parameters: stability and adaptability for both environments were obtained using the harmonic mean of the relative performance of the predicted genotypic values. High genotype by environment interactions were observed for most physic nut traits, indicating considerable influences of P availability on the phenotypic value. The genotype Paraíso simultaneously presented high adaptability and stability for aerial part dry matter, total dry matter, and P translocation efficiency. The genotype CNPAE-C2 showed a positive response to P fertilization by increasing both the total and aerial part dry matter.

English

The physic nut is an oleaginous plant that has distinguished itself as a drought tolerant native species, with a view to producing raw material for the biodiesel production. The purpose of the study reported here was to evaluate the quality of seeds and seedlings of five physic nut genotypes. The evaluated characteristics were: humidity content, mass of 1000 seeds, seed dimensions (using caliper gauge and sieves), germination tests, vigor tests (the first count of the germination test, electrical conductivity, accelerated ageing, seedling dry mass and length, emergence, emergence speed index and analysis of emerged seedlings). The experimental design was a completely randomized block with 4 replications. All data were submitted to analysis of variance by F test and the means were compared by the Tukey test at 5% probability. The physiological quality was not influenced by the seeds dimensions. The tests of accelerated ageing, emergence percentage, shoot dry mass, seedling length and dry mass were the bests at differentiating the genotypes. The Paraguacu genotype presented characteristics that were superior in relation to the others in the evaluations of accelerated ageing, root length and seedling total length. Key words: Jatropha curcas, germination, vigor, viability, seed size.

English

The objective of this study was to quantify the nutritional efficiency and responsiveness in relation to nitrogen of twelve genotypes of physic nut (Jatropha curcas L.) grown in soil without nitrogen supply and also with three levels of fertilization in a controlled environment. The experiment was conducted in factorial scheme 12 × 4 with four replications, the factors being: 12 genotypes of physic nut and four levels of nitrogen fertilization, studied in a randomized design. The plants were grown in pots, without restrictions, for 100 days and their dry matter and N contents were evaluated (for roots, leaves and total). Subsequently, the efficiency ratios for absorption, translocation, use and responsiveness in relation to the N supply were calculated. Overall, the nutritional efficiencies for nitrogen increase linearly with the increase of nitrogen supply in the soil. The genotypes CNPAE 161-II, CNPAE 167-II, CNPAE 180-I, CNPAE 255-I and CNPAE 300-I were classified as efficient and responsive to nitrogen fertilization being highlighted for plant breeding programs aiming to improve this agronomic trait. Key words: Physic nut, mineral nutrition, alpha parameter.

Genetic Variability among Genotypes of Physic Nut Regarding Seed Biometry

With probable center of origin in Brazil, the species Jatropha curcas L., known as physic nut, is a tropical oilseed with potential for cultivation aiming at the production of biodiesel. This study was conducted with the objective of investigating the genetic variability regarding the morphology of seeds of physic nut, using biometric analyses to identify variables that have potential for the study of the diversity of the species and the classification of genotypes. Seeds of 22 genotypes of physic nut, from the germplasm bank of Embrapa Agroenergia (Brazil) were evaluated regarding characteristics of size and mass. The genotypes of Jatropha curcas L. selected by the Brazilian breeding program presented high diversity for characteristics of the seeds, allowing the exploration of this genetic variability to classify genotypes in different groups. In addition, variables related to the biomass of the seeds present high relative contributions to the diversity observed in the genotypes.

Differential Growth of Genotypes of Physic Nut Conditioned by Nitrogen Fertilization

The adequate supply of nitrogen is essential for the plant metabolism. This nutrient has an irreplaceable role on the vegetative and reproductive growth of physic nut; therefore the correct management of the fertilization is very important, particularly in tropical regions, which present considerable losses of nitrogen by leaching and volatilization processes. This study was made with the objective of evaluating the growth of genotypes of physic nut conditioned by nitrogen fertilization. The experiment was conducted in controlled environment, following a factorial scheme 12 × 4, with 12 Brazilian genotypes of Jatropha curcas L. and 4 levels of nitrogen fertilization (0%, 50%, 100% and 150% of the recommendation), in completely randomized design, with four replications. The growth of the genotypes was evaluated at 100 days of cultivation. Positive response to the increase in the nitrogen supply was observed in most genotypes, with gain in plant height, stem diameter, number of leaves, leaf area and root volume. The levels of nitrogen fertilization promoted differential growth between genotypes, being possible to identify genotypes with superior growth for each level.

Genetic diversity and molecular characterization of physic nut genotypes from the active germplasm bank of the Agricultural Research Company of Minas Gerais, Brazil

The genetic diversity among 46 accessions of physic nut was estimated with Nei and Li’s similarity coefficient based on a collection of 69 random amplified polymorphic DNA (RAPD) sequences and 37 inter-simple sequence repeat (ISSR) polymorphic loci. The genetic distance between accessions ranged from 0.13 to 0.76, with an average genetic distance of 0.21. The most divergent genotypes were 86, 71 and 83. A dendrogram (generated by the unweighted pair group method with arithmetic mean, UPGMA) of the joint data matrix was constructed and presented only two phylogenetic groups, one of which contained only three individuals; the remaining group included 95.6% of the analyzed genotypes. The low genetic diversity measured in this study indicates the need to broaden the genetic base and increase the variability of this species. The amplification products generated by amplification of SSR primers were used to characterize toxicity alleles, and none of the accessions presented patterns characteristic of non-toxic accessions.

Genetic divergence in 3 and 4 year old genotypes of physic nut [Jatropha curcas(L.)

Fifty six germplasm lines of physic nut collected from Aravali hills of Southern Rajasthan were assessed for 26 characters recorded for two consecutive years during 2007 and 2008 on 3 and 4 year old plants. The values of V statistics were 12040 and 10950 in first and second year, respectively which showed significant difference between the genotypes over the characters. The two year values indicated that sufficient diversity was present among the 56 genotypes of physic nut. The 56 genotypes were grouped into 8 clusters using Euclidean2 values of 500 and 285 in the third and fourth year, respectively.The composition of clusters was slightly different in different years. With changing the age, genotypes also changed their cluster but most of the genotypes moved together and found place in one cluster. There was no relationship between genetic diversity and geographic distance. The contribution of vegetative characters towards genetic divergence was negligible.The characters like seed content, 100-seed weight, number of female flowers per inflorescence, oil content, kernel: shell ratio and weight per fruit were main contributors to total divergence. Cluster III and VIII in 3rd year and cluster VI and VIII in 4th year had maximum inter cluster distances. Cluster IV in 3rd year and cluster VIII in 4th year had highest mean values for maximum number of characters. Based on above results ARV-036 X ARV-020 and ARV-036 X ARV-023 are recommended for hybridization, as these genotypes showed good per se performance for seed yield and oil content and belong to the highly diverse clusters.

A differential Response of Physic Nut Genotypes Regarding Phosphorus Absorption and Utilization is Evidenced by a Comprehensive Nutrition Efficiency Analysis

The objective of this study was to evaluate the nutritional efficiency of phosphorus in physic nut (Jatropha curcas L.) genotypes, under controlled conditions. The experiment was arranged in a randomized block design, in a factorial scheme 10 x 2, using ten physic nut genotypes, two levels of phosphorus available in the soil (10 and 60 mg dm-3), and four replications. Cultivation consisted of a period of 100 days, with vegetative growth being evaluated in each experimental plot, with the dry matter mass values, phosphorus contents in the vegetative parts, nutritional efficiency indices, and alpha parameter also being obtained. The results show that the physic nut genotypes present greater vegetative growth, dry matter mass accumulation, P content, absorption efficiency and translocation at the high level of phosphorus available in the soil. Genotype CNPAE-C2 is the most efficient and responsive to phosphoric fertilization.

Estimate of genetic parameters and predicted gains with early selection of physic nut families

An initial evaluation of early selection of physic nut genotypes based on phenotypic data is presented. In order to predict the genetic gains with early selection, genetic parameters, e.g. additive genetic variance, were first obtained for grain yield along with other numerous traits. The results demonstrated that additive genetic variance exists not only for grain yield, which is considered to be the most important trait for oil and biodiesel production, but also for numerous other traits. The predicted genetic gains for grain yield, considering the selection of the 30, 20, 10 and 5 best families in the second crop year are respectively, 40.47, 48.43, 61.78 and 70.28%. With the selection of highly yielding physic nut genotypes indirectly genotypes with enhanced volume would be also selected, because yield exhibits moderate to high genetic correlations with height e canopy volume. The results here presented demonstrate the potential of the population gathered in the Brazilian physic nut germplasm bank for genetic breeding purposes and that superior physic nut families can be selected with high accuracy based on the evaluation of its second crop.

Seletividade de herbicidas pré-emergentes ao pinhão-manso (Jatropha curcas)

Nos últimos anos, a área cultivada com pinhão-manso tem se expandido no Brasil, tendo em vista a sua utilização na produção de biocombustíveis. Um dos problemas enfrentados pelos produtores é a escassez de informações sobre a tolerância do pinhão-manso aos herbicidas registrados no Brasil. Diante disso, objetivou-se avaliar a tolerância de genótipos de pinhão-manso a herbicidas aplicados em pré-emergência da cultura. O experimento foi instalado em blocos casualizados, com quatro repetições, em esquema fatorial 3 x 6. O fator A foi composto pelos genótipos de pinhão-manso (Filomena, Gonçalo e Paraguaçu), e o fator B, pelos herbicidas (isoxaflutole, oxyfluorfen, sulfentrazone, pendimethalin e tebuthiuron) mais uma testemunha sem aplicação de herbicida. A intoxicação dos genótipos pelos herbicidas foi avaliada aos 19, 32, 40, 48, 56 e 64 dias após a aplicação dos tratamentos (DAT). Aos 64 DAT, avaliaram-se a altura, a área foliar e a massa seca da parte aérea das plantas. Constatou-se que os genótipos de pinhão-manso apresentaram níveis variáveis de tolerância aos herbicidas estudados. Isoxaflutole e tebuthiuron causaram severas injúrias aos genótipos avaliados e influenciaram negativamente todas as variáveis estudadas. Oxyfluorfen e pendimethalin mostraram-se mais seletivos, devendo ser avaliados em novos estudos a fim de serem recomendados para a cultura.

Propagation Potentials of Genotypes and Different Physiological Ages of Stem Cuttings in Jatropha curcas L.

Propagation potentials of stem cuttings of different physiological ages and genotypes of physic nut (Jatropha curcas L.) were studied at UKM, Malaysia. Stem cuttings of the different physiological ages (hardwood, semi hardwood and soft wood) taken from five selected genotypes of Jatropha were planted in soil media (top soil). Data were collected on the attributes of the stem cuttings and then analyzed using computer based software, SAS, version 9.01, (2008). The study showed significant variability in shoot and root development and growth of shoots of the three physiological ages of cuttings and five genotypes. Semi hardwood stem cuttings had lower days to opening of new bud and shooting (4.8 and 11.7 d, respectively) as well as higher percentage of sprouted and rooted cuttings of 100% and 98.5%, respectively. Soft wood cuttings took more days to opening of new bud and shoot development in all five genotypes. Soft wood cuttings also showed lower percentage of rooted cuttings. Semi hard wood cuttings proved to be more suitable for the vegetative propagation of Jatropha curcas through stem cutting, which gave more than 98% success. Genotypic differences were observed in shooting and rooting of Jatropha. Genotype JC 14 performed better in all three types of cutting compared to other four genotypes.

Desempenho agronômico de genótipos de pinhão manso no Semiárido pernambucano

Com o objetivo de avaliar o comportamento silvicultural e a produtividade de genótipos de pinhão manso sob condições irrigadas no Semiárido nordestino, um experimento foi implantado na Fazenda Gabriela, localizada no Município de Santa Maria da Boa Vista, Pernambuco (PE). Usou-se o delineamento de blocos ao acaso com 10 tratamentos e três repetições. Os tratamentos constaram de 10 genótipos obtidos da seleção de plantas mais produtivas de um plantio introdutório de pinhão manso em Petrolina-PE. O espaçamento utilizado foi de 3,0 x 2,0m. Cada planta, por ocasião do plantio, foi adubada com 150g de NPK - fórmula 06:24:12. As plantas foram irrigadas semanalmente por gotejamento. Os resultados obtidos aos três meses de idade foram submetidos à análise de variância, sendo as médias comparadas pelo teste de Duncan, considerando-se uma probabilidade de 5%, para identificar a diferença significativa entre os genótipos. Os valores obtidos para os diferentes genótipos aos três meses de idade, para sobrevivência (100%), altura das plantas (1,3m) e número de inflorescências por planta (12), não apresentaram diferenças significativas, enquanto que o número de bifurcações, com variação de 3,6 a 5,3 bifurcações por planta, foi significativamente diferente. Por ter se sobressaído dentre os genótipos estudados na avaliação feita aos 12 meses quanto à altura de planta (2,7m), ao diâmetro do caule (6,3cm), ao número de frutos por planta (1.211) e à produção de sementes (3.542kg ha-1), o genótipo 2304 pode ser recomendado para pesquisas com melhoramento vegetal que visem ao aumento da produção de sementes da espécie J. curcas.