Morphological And Molecular Characterization Of Eggplant Lines For Resistant To Phomopsis Blight And Fruit Rot

The F4 lines of eggplant derived from the crosses of Dohazari G x BAU Begun-1 and Laffa S x BAU Begun-1 were evaluated for resistance to phomopsis blight and fruit rot under confined field conditions. The inoculated plants exhibited differential disease reactions. Among the parents, BAU Begun-1 was resistant whereas Dohazari G and Laffa S were susceptible to Phomopsis vexans. All the phenotypes of F4 progenies showed resistant reaction to the disease. Significant differences were observed among the phenotypes in all the yield components. High genotypic and phenotypic coefficient of variation, heritability and per cent genetic advance were estimated for number of fruits per plant, number of secondary branch per plant, fruit length and fruit breadth. Significant positive correlation was observed between yield contributing characters. Random amplified polymorphic DNA technique was used for assessing genetic variation and relationship among parent cultivars and their F4 progenies of eggplant. Amplification with five decamer primers generated 69.0% polymorphic bands. Comparatively higher genetic distance was observed between Laffa S vs. green globose (Dohazari G x BAU Begun-1). The dendogram constructed from Neis genetic distance produced two main clusters, the parent cultivars and six F4 lines formed cluster 1 and one line in cluster 2. F4 lines of the tested phenotypes showed similar disease reaction and divided into same sub cluster. The parent cultivars were different in case of disease reaction and finally divided into two groups, susceptible cultivars Laffa S and Dohazari G belonged to group 1 and the resistant parent BAU Begun-1 formed another group. Int. J. Agril. Res. Innov. & Tech. 3 (1): 35-46, June, 2013 DOI: http://dx.doi.org/10.3329/ijarit.v3i1.1605

Phenotypic and genotypic screening of rice genotypes at seedling stage for salt tolerance | Selección fenotípica y genotípica de genotipos de arroz para tolerancia a la salinidad en la etapa de plántulas

Selection for salinity tolerant genotypes of rice based on phenotypic performance alone is less reliable and will delay in progress in breeding. Recent advent of molecular markers, microsatellites or simple sequence repeats (SSRs), have been useful in finding salt tolerant rice genotypes. Three selected SSR markers already known to be polymorphic, viz., RM7075, RM336 and RM253, were used to evaluate rice genotypes for salt tolerance. Phenotypic and genotypic evaluation for salinity tolerance was done at the seedling stage. Phenotyping was done in hydroponic system using salinized (EC 12 dS/m) nutrient solution following IRRI standard protocol. Large variation in salinity tolerance among the rice germplasms was detected. Salt stress (EC 12 dS/m) reduced seedling height by 19.0% and total dry matter of tolerant lines by 40.6%, whereas, total dry matter of susceptible lines were reduced by 46.0-73.5%. All the tested markers were polymorphic and were able to discriminate salt tolerant genotypes from susceptible. The genotypes having similar banding pattern with Pokkali were considered as salt tolerant. Markers RM7075, RM336 and RM253 identified eight, nine and seven salt tolerant genotypes, respectively. Through phenotypic and genotypic study, three genotypes viz., Pokkali, TNDB-100 and THDB were identified as salt tolerant rice genotypes. These SSR markers might have sequence homology with salt tolerant rice genotypes and consequently the markers could able to identify salt tolerant rice genotypes from susceptible ones. Key words: rice, salinity tolerance, SSR markers, seedling stage. RESUMEN La selección para resistencia a la salinidad de genotipos de arroz, basada solamente en el comportamiento fenotípico, es menos confiable y retarda el avance en el mejoramiento. Se han utilizado avances recientes en marcadores moleculares, microsatélites o repeticiones de secuencias simples (SSR por sus siglas en inglés) para determinar genotipos de arroz tolerantes a la salinidad. Se utilizaron tres marcadores SSR viz., RM7075, RM336 y RM253 para evaluar genotipos de arroz para tolerancia a la salinidad. La evaluación fenotípica y genotípica para la tolerancia a la salinidad se realizó en la etapa de plántula. La fenotipificación de once genotipos se realizó en un sistema hidropónico utilizando solución nutritiva salinizada (CE 12 dS/m). Se siguió el protocolo estandarizado del IRRI para evaluar la tolerancia a la salinidad. Se detectó una gran variación en la tolerancia a la salinidad entre el germoplasma de arroz. La altura de las plántulas y la materia seca total de las líneas tolerantes se redujeron en un 19,0 y 40,6%, respectivamente, bajo estrés salino (CE 12 dS/m), en tanto que las de las líneas susceptibles se redujeron en un 46,0% y 73,5%, respectivamente. Los marcadores mostraron polimorfismo y fueron capaces de discriminar los genotipos tolerantes a la salinidad de aquellos susceptibles. Los genotipos con un patrón similar de bandas a Pokkali se consideraron como tolerantes a la salinidad. Los marcadores SSR (RM7075, RM336 y RM253) identificaron ocho, nueve y siete genotipos tolerantes a la salinidad, respectivamente. A través del estudio fenotípico y genotípico, tres genotipos viz., Pokkali, TNDB-100 y THDB se identificaron como cultivares de arroz tolerantes a la salinidad. Estos marcadores SSR podrían tener homología de secuencias con genotipos de arroz tolerantes a la salinidad y por consiguiente, los marcadores podrían ser capaces de identificar genotipos de arroz tolerantes a la salinidad de aquellos susceptibles. Palabras clave: Arroz, tolerancia a la salinidad, marcadores SSR, etapa de plántulas

Evaluation of rice (Oryza sativa L.) genotypes grown under combined salinity and submergence stresses based on vegetative stage phenotyping

Sixteen rice genotypes were screened against combined salinity and submergence stresses to find out potential salt-submergence tolerant genotypes. Rice seedlings were subjected to submergence stress including two salinity levels viz., EC-6 dSm-1 and EC-8 dSm-1 for 10 days. Imposition of combined stress considerably decreased the growth parameters in rice seedlings, however ACM-18, ACM-35, and RC-251 demonstrated the maximum value for growth attributes such as leaf live (%), root and shoot length, plant fresh and dry biomass. The results of correlation and regression revealed a significant and negative association of leaf lives (%), root length, fresh weight of root and shoot, and root dry weight with mean tolerance score under combined stress indicating their importance as the useful descriptors for the selection. Euclidean clustering was categorized the rice genotypes into three major clusters, i.e., A-susceptible, B-tolerant and moderately tolerant, and C-highly tolerant. Results of cluster analysis showed that the highly tolerant genotypes namely ACM-18, ACM-35, and RC-251 were placed in the same cluster. Similar results were further confirmed by principal component analysis having the highly tolerant genotypes in the same group. Combining the morphological and multivariate analysis, ACM-18, ACM-35, and RC-251 were selected as promising genotypes for developing high-yielding salt-submergence tolerant rice

Genetic variability, heritability, correlation and path analyses of yield components in traditional rice (Oryza sativa L.) landraces

The presence of sufficient genetic variability, the knowledge of nature of association among different characters and relative contribution of different characters to yield is a prerequisite to any breeding programme. The aim of the present study was to estimate genetic parameters of thirteen yield and yield attributing traits in 40 landraces of rice with a view to select better yield attributes in rice. The higher value of phenotypic co-efficient of variation (PCV) compared to the corresponding genotypic coefficient of variation (GCV) for all the studied traits indicated that there was an influence of the environment. Number of unfilled grains per panicle exhibited high estimates of PCV and GCV followed by number of filled grains per panicle, number of grains per panicle, flag leaf area. High heritability coupled with high genetic advance was observed in flag leaf area, pollen fertility, number of grains per panicle and number of filled grains per panicle which reflected that the direct selection of these characters based on phenotypic expression by simple selection method for yield improvement would be more reliable Grain yield per plant showed significant and positive association with days to 50% flowering, days to maturity, flag leaf area, number of total tillers per hill, number of effective tillers per hill, pollen fertility, number of grains per panicle, number of filled grains per panicle indicating selection of these characters for yield improvement may be rewarding. Both at phenotypic and genotypic level, days to 50% flowering, flag leaf area, number of effective tillers per hill, pollen fertility, panicle length, number of grains per panicle and 100 seed weight had direct positive effect on yield per plant indicating their importance during selection in yield improvement program. Moreover, the information generated from this study, can be exploited in future rice breeding program

MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF EGGPLANT LINES FOR RESISTANT TO PHOMOPSIS BLIGHT AND FRUIT ROT

The F4 lines of eggplant derived from the crosses of Dohazari G x BAU Begun-1 and Laffa S x BAU Begun-1 were evaluated for resistance to phomopsis blight and fruit rot under confined field conditions. The inoculated plants exhibited differential disease reactions. Among the parents, BAU Begun-1 was resistant whereas Dohazari G and Laffa S were susceptible to Phomopsis vexans. All the phenotypes of F4 progenies showed resistant reaction to the disease. Significant differences were observed among the phenotypes in all the yield components. High genotypic and phenotypic coefficient of variation, heritability and per cent genetic advance were estimated for number of fruits per plant, number of secondary branch per plant, fruit length and fruit breadth. Significant positive correlation was observed between yield contributing characters. Random amplified polymorphic DNA technique was used for assessing genetic variation and relationship among parent cultivars and their F4 progenies of eggplant. Amplification with five decamer primers generated 69.0% polymorphic bands. Comparatively higher genetic distance was observed between Laffa S vs. green globose (Dohazari G x BAU Begun-1). The dendogram constructed from Nei’s genetic distance produced two main clusters, the parent cultivars and six F4 lines formed cluster 1 and one line in cluster 2. F4 lines of the tested phenotypes showed similar disease reaction and divided into same sub cluster. The parent cultivars were different in case of disease reaction and finally divided into two groups, susceptible cultivars Laffa S and Dohazari G belonged to group 1 and the resistant parent BAU Begun-1 formed another group

Estudio de la variabilidad presente en germoplasma de tártago (Ricinus communis L.) en cuanto a racimos, frutos y semillas

Castor bean (Ricinus communis L.) is an oil crop cultivated for industrial use and as an ornamental plant. Lately, the interest for this species has increased for being a raw material for the production of biodiesel, an ecological less pollutant fuel. The resistance to drought is its outstanding characteristic, standing as an opportunity for agricultural development in arid and semiarid areas. In this study the variability of 13 accessions of castor bean is reported based on qualitative and quantitative traits: raceme (shape, compaction, length of primary, number of fruits per raceme, weight of seeds per raceme, number seed per raceme), capsules (dehiscence, spines, 100 weight, color of immature fruits) and seeds (weight of 100, weight in 100 fruits, width, length, width/long and oil content). Principal components analysis explained 87% of the variability with the three first components. Hierarchic classification showed four clusters of accessions, grouping materials based mainly on seeds and fruits dimensions and weight. Variability was also found based on qualitative traits of fruit and racemes. This collection includes accessions of spineless, smooth and indehiscent capsules with different degrees of dehiscence and drop of capsules, waxy or not. The variability found in the studied collection can provide the base material to be used in breeding programs of the species.El tártago (Ricinus communis L.) es cultivado como oleaginosa de uso industrial y planta ornamental. Tanto en Venezuela como a nivel mundial se ha aumentado el interés por esta especie, por ser materia prima para la producción de biodiesel, combustible ecológico menos contaminante. La resistencia a la sequía es su característica más destacada, pudiendo ser sembrado en zonas áridas y semiáridas. En el presente trabajo se reporta la variabilidad encontrada en 13 accesiones de tártago sobre la base de caracteres cualitativos y cuantitativos: forma del racimo, compactación de los frutos, longitud del racimo primario, número de frutos/racimo, peso de semilla/racimo, número de semillas/racimo, dehiscencia y espinosidad de los frutos, peso de 100 frutos, color de frutos inmaduros, peso de 100 semillas, peso de semilla en 100 frutos, ancho, largo, relación ancho/largo de las semillas y contenido de aceite de las semillas. El análisis de componentes principales explicó el 87% de la variabilidad encontrada en los primeros tres componentes. La clasificación jerárquica ascendente mostró cuatro grupos bien definidos de accesiones determinadas principalmente por caracteres de peso y dimensión de frutos y semillas. En los genotipos estudiados también se encontró una importante variabilidad sobre la base de caracteres cualitativos de frutos y racimos. La colección incluye accesiones de frutos sin acúleos (espinas) y lisos, de espinosidad densa a rala, frutos indehiscentes y persistentes, racimos cónicos, cilíndricos y globosos, desde muy ralos hasta muy compactos, con y sin cera. Esta variación puede hacer del germoplasma estudiado un material base para su uso directo y potencial en programas de mejoramiento del cultivo

Selección fenotípica y genotípica de genotipos de arroz para tolerancia a la salinidad en la etapa de plántulas

Selection for salinity tolerant genotypes of rice based on phenotypic performance alone is less reliable and will delay in progress in breeding. Recent advent of molecular markers, microsatellites or simple sequence repeats (SSRs), have been useful in finding salt tolerant rice genotypes. Three selected SSR markers already known to be polymorphic, viz., RM7075, RM336 and RM253, were used to evaluate rice genotypes for salt tolerance. Phenotypic and genotypic evaluation for salinity tolerance was done at the seedling stage. Phenotyping was done in hydroponic system using salinized (EC 12 dS/m) nutrient solution following IRRI standard protocol. Large variation in salinity tolerance among the rice germplasms was detected. Salt stress (EC 12 dS/m) reduced seedling height by 19.0% and total dry matter of tolerant lines by 40.6%, whereas, total dry matter of susceptible lines were reduced by 46.0-73.5%. All the tested markers were polymorphic and were able to discriminate salt tolerant genotypes from susceptible. The genotypes having similar banding pattern with Pokkali were considered as salt tolerant. Markers RM7075, RM336 and RM253 identified eight, nine and seven salt tolerant genotypes, respectively. Through phenotypic and genotypic study, three genotypes viz., Pokkali, TNDB-100 and THDB were identified as salt tolerant rice genotypes. These SSR markers might have sequence homology with salt tolerant rice genotypes and consequently the markers could able to identify salt tolerant rice genotypes from susceptible ones.La selección para resistencia a la salinidad de genotipos de arroz, basada solamente en el comportamiento fenotípico, es menos confiable y retarda el avance en el mejoramiento. Se han utilizado avances recientes en marcadores moleculares, microsatélites o repeticiones de secuencias simples (SSR por sus siglas en inglés) para determinar genotipos de arroz tolerantes a la salinidad. Se utilizaron tres marcadores SSR viz., RM7075, RM336 y RM253 para evaluar genotipos de arroz para tolerancia a la salinidad. La evaluación fenotípica y genotípica para la tolerancia a la salinidad se realizó en la etapa de plántula. La fenotipificación de once genotipos se realizó en un sistema hidropónico utilizando solución nutritiva salinizada (CE 12 dS/m). Se siguió el protocolo estandarizado del IRRI para evaluar la tolerancia a la salinidad. Se detectó una gran variación en la tolerancia a la salinidad entre el germoplasma de arroz. La altura de las plántulas y la materia seca total de las líneas tolerantes se redujeron en un 19,0 y 40,6%, respectivamente, bajo estrés salino (CE 12 dS/m), en tanto que las de las líneas susceptibles se redujeron en un 46,0% y 73,5%, respectivamente. Los marcadores mostraron polimorfismo y fueron capaces de discriminar los genotipos tolerantes a la salinidad de aquellos susceptibles. Los genotipos con un patrón similar de bandas a Pokkali se consideraron como tolerantes a la salinidad. Los marcadores SSR (RM7075, RM336 y RM253) identificaron ocho, nueve y siete genotipos tolerantes a la salinidad, respectivamente. A través del estudio fenotípico y genotípico, tres genotipos viz., Pokkali, TNDB-100 y THDB se identificaron como cultivares de arroz tolerantes a la salinidad. Estos marcadores SSR podrían tener homología de secuencias con genotipos de arroz tolerantes a la salinidad y por consiguiente, los marcadores podrían ser capaces de identificar genotipos de arroz tolerantes a la salinidad de aquellos susceptibles

Morpho-Genetic Study and Detection of Boron Toxicity Tolerance of Wild Wheat Genotypes

<p>The occurrence of boron toxicity becomes a major constraint in cereal production in the world, thus cause significant yield loss particularly in wheat, one of the most susceptible crops to boron toxicity. Development of tolerant variety is now of utmost importance since agronomic management of soil boron is becoming ineffective to mitigate the toxicity. Due to narrow genetic base of the existing wheat cultivars, genetic variation for this character was poorly reported. The present study was devoted to identify such variation by using two different genetic background of wheat including <em>Aegilops</em> and <em>Triticum</em>, which could be readily used in wheat breeding program. Morphological and genetic screening revealed that two species <em>Ae. longissima </em>and <em>Ae. sharonensis</em> expressed tolerance against boron toxicity. The molecular marker analysis such as unweighted pair group method and principal coordinate analysis confirmed these two species<em> </em>to be more tolerant to excessive boron with higher root length. Their derivatives genotypes TL-09 and TL-17 were found to explained considerable tolerance to boron. On other hand, among the SSR markers used, Xgwm192 was the most robust in identifying boron tolerance polymorphism. The diversity and variability observed in this work could open new avenue in developing B toxicity tolerant wheat variety.</p

Screening of local landraces of rice (Oryza sativa L.) at the seedling stage for salinity tolerance based on genetic divergence analysis

The presence of genetic diversity is a prerequisite for improvement of any crops. Salinity is a severe threat for the production of rice which can be solved by improving tolerant variety through breeding programs. Twenty-five rice genotypes were evaluated to explore the genetic diversity of growth param- eters by imposing three levels of salinity treatments (0 dS m&#8722;1, 7 dS m&#8722;1 and 12 dS m&#8722;1 EC) with three replications following completely randomized design (CRD).The genotypes were categorized into five major sub-clusters considering ten morphological traits using the non-hierarchical Euclidean distances revealed that maximum 10 genotypes viz., Moynamoti, Badshavog, Pangash, Suvash, Moghabalam,Sadaswarna, Bina dhan-8, Chinikani, Ash- failand, and Rajashail were found in cluster III while lowest two genotypes namely Lalbat and M-171 were found in cluster IV. The results of the cluster analysis also reported that the inter-cluster distances in all the cases were greater than the intra-cluster distances. The highest intra-cluster diversity was observed in cluster IV (6.30) whereas lowest intra-cluster diversity was found in cluster I (4.16). The maximum inter-cluster distance was found between cluster II and V (15.45) where minimum inter-cluster distance was observed between cluster I and II (6.39). Root fresh weight contributed great- est (19%) to the divergence of genotypes where root length contributed least (0.33%) to the total diversity of the genotypes. The cluster means value for most of the morphological traits was maximum in cluster II reflecting that the genotypes grouped in cluster II could be selected as salt tolerant genotypes at the seedling stages for the cultivation in the coastal area of Bangladesh. [Fundam Appl Agric 2019; 4(2.000): 849-857