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1.
Crit Rev Biotechnol ; 39(7): 904-923, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31303070

RESUMEN

A large number of rice agronomic traits are complex, multi factorial and polygenic. As the mechanisms and genes determining grain size and yield are largely unknown, the identification of regulatory genes related to grain development remains a preeminent approach in rice genetic studies and breeding programs. Genes regulating cell proliferation and expansion in spikelet hulls and participating in endosperm development are the main controllers of rice kernel elongation and grain size. We review here and discuss recent findings on genes controlling rice grain size and the mechanisms, epialleles, epigenomic variation, and assessment of controlling genes using genome-editing tools relating to kernel elongation.


Asunto(s)
Grano Comestible/crecimiento & desarrollo , Grano Comestible/genética , Oryza/crecimiento & desarrollo , Oryza/genética , Genes de Plantas , Proteínas de Plantas/genética
2.
Mol Biol Rep ; 46(1): 1519-1532, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30628024

RESUMEN

Breeding for disease resistant varieties remains very effective and economical in controlling the bacterial leaf blight (BLB) of rice. Breeders have played a major role in developing resistant rice varieties against the BLB infection which has been adjudged to be a major disease causing significant yield reduction in rice. It would be difficult to select rice crops with multiple genes of resistance using the conventional approach alone. This is due to masking effect of genes including epistasis. In addition, conventional breeding takes a lot of time before a gene of interest can be introgressed. Linkage drag is also a major challenge in conventional approach. Molecular breeding involving markers has facilitated the characterization and introgression of BLB disease resistance genes. Biotechnology has brought another innovation in form of genetic engineering (transgenesis) of rice. Although, molecular breeding cannot be taken as a substitute for conventional breeding, molecular approach for combating BLB disease in rice is worthwhile given the demand for increased production of rice in a fast growing population of our society. This present article highlights the recent progress from conventional to molecular approach in breeding for BLB disease resistant rice varieties.


Asunto(s)
Resistencia a la Enfermedad , Oryza/microbiología , Fitomejoramiento , Enfermedades de las Plantas/microbiología , Hojas de la Planta/microbiología , Xanthomonas/fisiología , Oryza/genética , Xanthomonas/genética , Xanthomonas/patogenicidad
4.
BMC Complement Altern Med ; 17(1): 181, 2017 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-28359331

RESUMEN

BACKGROUND: This study was aimed to evaluate antioxidant and α-glucosidase inhibitory activity, with a subsequent analysis of total phenolic and total flavonoid content of methanol extract and its derived fractions from Clinacanthus nutans accompanied by comprehensive phytochemical profiling. METHODS: Liquid-liquid partition chromatography was used to separate methanolic extract to get hexane, ethyl acetate, butanol and residual aqueous fractions. The total antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazy (DPPH) radical scavenging and ferric reducing antioxidant power assay (FRAP). The antidiabetic activity of methanol extract and its consequent fractions were examined by α-glucosidase inhibitory bioassay. The chemical profiling was carried out by gas chromatography coupled with quadrupole time-of-flight mass spectrometry (GC Q-TOF MS). RESULTS: The total yield for methanol extraction was (12.63 ± 0.98) % (w/w) and highest fractionated value found for residual aqueous (52.25 ± 1.01) % (w/w) as compared to the other fractions. Significant DPPH free radical scavenging activity was found for methanolic extract (63.07 ± 0.11) % and (79.98 ± 0.31) % for ethyl acetate fraction among all the fractions evaluated. Methanol extract was the most prominent in case of FRAP (141.89 ± 0.87 µg AAE/g) whereas most effective reducing power observed in ethyl acetate fraction (133.6 ± 0.2987 µg AAE/g). The results also indicated a substantial α-glucosidase inhibitory activity for butanol fraction (72.16 ± 1.0) % and ethyl acetate fraction (70.76 ± 0.49) %. The statistical analysis revealed that total phenolic and total flavonoid content of the samples had the significant (p < 0.05) impact on DPPH free radical scavenging and α-glucosidase inhibitory activity. CONCLUSION: Current results proposed the therapeutic potential of Clinacanthus nutans, especially ethyl acetate and butanol fraction as chemotherapeutic agent against oxidative related cellular damages and control the postprandial hyperglycemia. The phytochemical investigation showed the existence of active constituents in Clinacanthus nutans extract and fractions.


Asunto(s)
Acanthaceae/química , Antioxidantes/química , Inhibidores de Glicósido Hidrolasas/química , Extractos Vegetales/química , Antioxidantes/aislamiento & purificación , Antioxidantes/metabolismo , Inhibidores de Glicósido Hidrolasas/aislamiento & purificación , Inhibidores de Glicósido Hidrolasas/metabolismo , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/metabolismo , Tallos de la Planta/química , alfa-Glucosidasas/química , alfa-Glucosidasas/metabolismo
5.
Genet Mol Res ; 16(1)2017 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-28128411

RESUMEN

Rice (Oryza sativa L.) blast disease is one of the most destructive rice diseases in the world. The fungal pathogen, Magnaporthe oryzae, is the causal agent of rice blast disease. Development of resistant cultivars is the most preferred method to achieve sustainable rice production. However, the effectiveness of resistant cultivars is hindered by the genetic plasticity of the pathogen genome. Therefore, information on genetic resistance and virulence stability are vital to increase our understanding of the molecular basis of blast disease resistance. The present study set out to elucidate the resistance pattern and identify potential simple sequence repeat markers linked with rice blast disease. A backcross population (BC2F1), derived from crossing MR264 and Pongsu Seribu 2 (PS2), was developed using marker-assisted backcross breeding. Twelve microsatellite markers carrying the blast resistance gene clearly demonstrated a polymorphic pattern between both parental lines. Among these, two markers, RM206 and RM5961, located on chromosome 11 exhibited the expected 1:1 testcross ratio in the BC2F1 population. The 195 BC2F1 plants inoculated against M. oryzae pathotype P7.2 showed a significantly different distribution in the backcrossed generation and followed Mendelian segregation based on a single-gene model. This indicates that blast resistance in PS2 is governed by a single dominant gene, which is linked to RM206 and RM5961 on chromosome 11. The findings presented in this study could be useful for future blast resistance studies in rice breeding programs.


Asunto(s)
Genes de Plantas , Marcadores Genéticos , Repeticiones de Microsatélite , Oryza/genética , Enfermedades de las Plantas/genética , Cruzamiento , Cruzamientos Genéticos , Resistencia a la Enfermedad/genética
6.
Crit Rev Biotechnol ; 36(2): 353-67, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-25394538

RESUMEN

Rice blast disease, which is caused by the fungal pathogen Magnaporthe oryzae, is a recurring problem in all rice-growing regions of the world. The use of resistance (R) genes in rice improvement breeding programmes has been considered to be one of the best options for crop protection and blast management. Alternatively, quantitative resistance conferred by quantitative trait loci (QTLs) is also a valuable resource for the improvement of rice disease resistance. In the past, intensive efforts have been made to identify major R-genes as well as QTLs for blast disease using molecular techniques. A review of bibliographic references shows over 100 blast resistance genes and a larger number of QTLs (∼500) that were mapped to the rice genome. Of the blast resistance genes, identified in different genotypes of rice, ∼22 have been cloned and characterized at the molecular level. In this review, we have summarized the reported rice blast resistance genes and QTLs for utilization in future molecular breeding programmes to introgress high-degree resistance or to pyramid R-genes in commercial cultivars that are susceptible to M. oryzae. The goal of this review is to provide an overview of the significant studies in order to update our understanding of the molecular progress on rice and M. oryzae. This information will assist rice breeders to improve the resistance to rice blast using marker-assisted selection which continues to be a priority for rice-breeding programmes.


Asunto(s)
Mapeo Cromosómico , Clonación Molecular , Resistencia a la Enfermedad/genética , Genes de Plantas/genética , Magnaporthe/patogenicidad , Oryza , Oryza/genética , Oryza/microbiología , Oryza/fisiología , Proteínas de Plantas/genética
7.
Crit Rev Biotechnol ; 36(1): 165-74, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-25198435

RESUMEN

The blast fungus, Magnaporthe oryzae, causes serious disease on a wide variety of grasses including rice, wheat and barley. The recognition of pathogens is an amazing ability of plants including strategies for displacing virulence effectors through the adaption of both conserved and variable pathogen elicitors. The pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI) were reported as two main innate immune responses in plants, where PTI gives basal resistance and ETI confers durable resistance. The PTI consists of extracellular surface receptors that are able to recognize PAMPs. PAMPs detect microbial features such as fungal chitin that complete a vital function during the organism's life. In contrast, ETI is mediated by intracellular receptor molecules containing nucleotide-binding (NB) and leucine rich repeat (LRR) domains that specifically recognize effector proteins produced by the pathogen. To enhance crop resistance, understanding the host resistance mechanisms against pathogen infection strategies and having a deeper knowledge of innate immunity system are essential. This review summarizes the recent advances on the molecular mechanism of innate immunity systems of rice against M. oryzae. The discussion will be centered on the latest success reported in plant-pathogen interactions and integrated defense responses in rice.


Asunto(s)
Interacciones Huésped-Patógeno/inmunología , Magnaporthe/patogenicidad , Oryza/inmunología , Inmunidad de la Planta/genética , Quitina/genética , Quitina/inmunología , Magnaporthe/inmunología , Oryza/crecimiento & desarrollo , Oryza/microbiología , Moléculas de Patrón Molecular Asociado a Patógenos/inmunología
8.
Mol Biol Rep ; 43(12): 1347-1358, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27585572

RESUMEN

Ginger is an economically important and valuable plant around the world. Ginger is used as a food, spice, condiment, medicine and ornament. There is available information on biochemical aspects of ginger, but few studies have been reported on its molecular aspects. The main objective of this review is to accumulate the available molecular marker information and its application in diverse ginger studies. This review article was prepared by combing material from published articles and our own research. Molecular markers allow the identification and characterization of plant genotypes through direct access to hereditary material. In crop species, molecular markers are applied in different aspects and are useful in breeding programs. In ginger, molecular markers are commonly used to identify genetic variation and classify the relatedness among varieties, accessions, and species. Consequently, it provides important input in determining resourceful management strategies for ginger improvement programs. Alternatively, a molecular marker could function as a harmonizing tool for documenting species. This review highlights the application of molecular markers (isozyme, RAPD, AFLP, SSR, ISSR and others such as RFLP, SCAR, NBS and SNP) in genetic diversity studies of ginger species. Some insights on the advantages of the markers are discussed. The detection of genetic variation among promising cultivars of ginger has significance for ginger improvement programs. This update of recent literature will help researchers and students select the appropriate molecular markers for ginger-related research.


Asunto(s)
Polimorfismo Genético , Zingiber officinale/genética , Animales , ADN de Plantas/genética , Marcadores Genéticos , Humanos , Repeticiones de Microsatélite , Filogenia , Análisis de Secuencia de ADN
9.
Biol Res ; 49: 24, 2016 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-27090643

RESUMEN

This study was undertaken to determine the effects of varied salinity regimes on the morphological traits (plant height, number of leaves, number of flowers, fresh and dry weight) and major mineral composition of 13 selected purslane accessions. Most of the morphological traits measured were reduced at varied salinity levels (0.0, 8, 16, 24 and 32 dS m(-1)), but plant height was found to increase in Ac1 at 16 dS m(-1) salinity, and Ac13 was the most affected accession. The highest reductions in the number of leaves and number of flowers were recorded in Ac13 at 32 dS m(-1) salinity compared to the control. The highest fresh and dry weight reductions were noted in Ac8 and Ac6, respectively, at 32 dS m(-1) salinity, whereas the highest increase in both fresh and dry weight was recorded in Ac9 at 24 dS m(-1) salinity compared to the control. In contrast, at lower salinity levels, all of the measured mineral levels were found to increase and later decrease with increasing salinity, but the performance of different accessions was different depending on the salinity level. A dendrogram was also constructed by UPGMA based on the morphological traits and mineral compositions, in which the 13 accessions were grouped into 5 clusters, indicating greater diversity among them. A three-dimensional principal component analysis also confirmed the output of grouping from cluster analysis.


Asunto(s)
Minerales/análisis , Portulaca/anatomía & histología , Portulaca/química , Salinidad , Calcio/análisis , Flores/anatomía & histología , Hierro/análisis , Magnesio/análisis , Fósforo/análisis , Hojas de la Planta/anatomía & histología , Potasio/análisis , Valores de Referencia , Tolerancia a la Sal , Sodio/análisis , Zinc/análisis
10.
Genet Mol Res ; 14(4): 18140-52, 2015 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-26782461

RESUMEN

To examine the impact of regional and seasonal variations on the incidence and severity of sheath rot, a major seed-borne disease of rice caused by Sarocladium oryzae, data on incidence and severity were collected from 27 selected fields in the Gazipur, Rangpur, Bogra, Chittagong, Comilla, Gopalgonj, Jessore, Manikgonj, and Bhola districts of Bangladesh in rain-fed and irrigated conditions. Cultural variability of 29 pathogen isolates obtained from 8 different locations was studied on potato dextrose agar (PDA) and genetic variability was determined by DNA fingerprinting using variable number tandem repeat-polymerase chain reaction markers. Overall, disease incidence and severity were higher in irrigated rice. Disease incidence and severity were highest in the Bhola district in rain-fed rice and lowest in irrigated rice. Mycelial growth of 29 representative isolates was found to vary on PDA and the isolates were divided into 6 groups. The range of the overall size of conidia of the selected isolates was 2.40-7.20 x 1.20-2.40 µm. Analysis of the DNA fingerprint types of the 29 isolates of S. oryzae, obtained from the amplification reactions, revealed 10 fingerprinting types (FPTs) that were 80% similar. FPT-1 was the largest group and included 13 isolates (44.8%), while FPT-2 was the third largest group and included 3 isolates. Each of FPT-3, 4, 5, and 6 included only 1 isolate. We observed no relationship between cultural and genetic groupings.


Asunto(s)
Genética de Población , Hypocreales/genética , Oryza/microbiología , Enfermedades de las Plantas/genética , Dermatoglifia del ADN/métodos , Ecología , Variación Genética , Interacciones Huésped-Patógeno/genética , Hypocreales/patogenicidad , Oryza/genética , Enfermedades de las Plantas/microbiología , Semillas/genética , Semillas/microbiología
11.
Genet Mol Res ; 14(4): 17007-18, 2015 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-26681048

RESUMEN

Disease susceptibility and genetic variability in 10 eggplant genotypes were studied after inoculating Phomopsis vexans under confined field conditions. Random amplified polymorphic DNA (RAPD) markers were used to assess genetic variation and relationships among eggplant genotypes. The disease index of leaves ranged 0.208-13.79%, while fruit infection ranged 2.15-42.76%. Two varieties, Dohazari G and Laffa S, were found to be susceptible, 6 were moderately resistant, 1 was moderately susceptible, and BAU Begun-1 was resistant to P. vexans. Amplification of genomic DNA by using 3 RAPD primers produced 20 bands: 14 (70%) were polymorphic and 6 (30%) were monomorphic. The highest intra-variety similarity indices values were found in ISD 006, Ishurdi L, Jessore L, and BAU Begun-1 (100%), while the lowest was in Dohazari G (90%). The lowest genetic distance (0.0513) and the highest genetic identity (0.9500) were observed between the ISD 006 and Ishurdi L combinations. A comparatively higher genetic distance (0.3724) and the lowest genetic identity (0.6891) were observed between the ISD 006 and Dohazari G combinations. A dendogram was constructed based on Nei's genetic distance, which produced 2 main clusters of the genotypes - Cluster I: ISD 006, Ishurdi L, Marich begun L, BAU Begun-1, Marich begun S, and Chega and Cluster 2: Laffa S, Dohazari G, Jessore L, and Singhnath. Genetic variation and its relationship with disease susceptibility were assessed using RAPD markers, to develop disease-resistant varieties and improve eggplant crops.


Asunto(s)
Marcadores Genéticos , Predisposición Genética a la Enfermedad , Variación Genética , Enfermedades de las Plantas/genética , Solanum melongena/genética , Ascomicetos , Resistencia a la Enfermedad/genética , Evolución Molecular , Filogenia , Enfermedades de las Plantas/microbiología , Reacción en Cadena de la Polimerasa , Técnica del ADN Polimorfo Amplificado Aleatorio , Solanum melongena/clasificación
12.
Genet Mol Res ; 14(4): 12205-16, 2015 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-26505369

RESUMEN

The genetic evaluation of oil palm germplasm collections is required for insight into the variability among populations. The information obtained is also useful for incorporating new genetic materials into current breeding programs. Single nucleotide polymorphisms (SNPs) have been widely used in many plant genetic studies due to the availability of large numbers of genomic sequences and expressed sequence tags. The present study examined 219 oil palms collected from two natural Angolan populations, a few hundred kilometers apart. A total of 62 SNPs were designed from oil palm genomic sequences and converted to cleaved amplified polymorphic sequence (CAPS). Of these, nine were found to be informative across the two populations. The nine informative SNPs revealed mean major allele frequency of 0.693. The average expected and observed heterozygosities were 0.398 and 0.400, respectively. The mean polymorphism information content was 0.315 (ranging between 0.223 and 0.375). None of the loci deviated from Hardy-Weinberg equilibrium and no rare alleles were detected. In cluster analysis using unweighted pair group method with arithmetic, the 219 oil palms fell into two clusters. This was further supported by the population structure analysis result (K = 2), suggesting that the samples were divided into two main genetic groups. However, the two groups did not coincide with the geographic populations. Analysis of molecular variance indicated that within-population variation contributed 93% of the total genetic variation. This study showed that SNP-based CAPS markers are useful for studying the genetic diversity of oil palm and have potential application for marker-trait association studies.


Asunto(s)
Arecaceae/genética , Marcadores Genéticos/genética , Variación Genética/genética , Polimorfismo de Nucleótido Simple/genética , Arecaceae/clasificación
13.
Mol Biol Rep ; 41(11): 7395-411, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25085039

RESUMEN

Common purslane (Portulaca oleracea), also known as pigweed, fatweed, pusle, and little hogweed, is an annual succulent herb in the family Portulacaceae that is found in most corners of the globe. From the ancient ages purslane has been treated as a major weed of vegetables as well as other crops. However, worldwide researchers and nutritionists have studied this plant as a potential vegetable crop for humans as well as animals. Purslane is a nutritious vegetable with high antioxidant properties and recently has been recognized as the richest source of α-linolenic acid, essential omega-3 and 6 fatty acids, ascorbic acid, glutathione, α-tocopherol and ß-carotene. The lack of vegetable sources of ω-3 fatty acids has resulted in a growing level of attention to introduce purslane as a new cultivated vegetable. In the rapid-revolutionizing worldwide atmosphere, the ability to produce improved planting material appropriate to diverse and varying rising conditions is a supreme precedence. Though various published reports on morphological, physiological, nutritional and medicinal aspects of purslane are available, research on the genetic improvement of this promising vegetable crop are scant. Now it is necessary to conduct research for the genetic improvement of this plant. Genetic improvement of purslane is also a real scientific challenge. Scientific modernization of conventional breeding with the advent of advance biotechnological and molecular approaches such as tissue culture, protoplast fusion, genetic transformation, somatic hybridization, marker-assisted selection, qualitative trait locus mapping, genomics, informatics and various statistical representation have opened up new opportunities of revising the relationship between genetic diversity, agronomic performance and response to breeding for varietal improvement. This review is an attempt to amalgamate the assorted scientific information on purslane propagation, cultivation, varietal improvement, nutrient analyses, medicinal uses and to describe prospective research especially for genetic improvement of this crop.


Asunto(s)
Agricultura/métodos , Cruzamiento/métodos , Productos Agrícolas , Ingeniería Genética/métodos , Valor Nutritivo/genética , Portulaca/crecimiento & desarrollo , Portulaca/genética , Ácidos Grasos Omega-3/análisis , Ingeniería Genética/tendencias , Portulaca/química
14.
Genet Mol Res ; 13(2): 2426-37, 2014 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-24781997

RESUMEN

Twelve introgressed oil palm (Elaeis guineensis) progenies of Nigerian dura x Deli dura were evaluated for bunch yield, yield attributes, bunch quality components and vegetative characters at the Malaysian Palm Oil Board Research Station, in Keratong, Pahang, Malaysia. Analysis of variance revealed significant to highly significant genotypic differences, indicating sufficient genetic variability among the progenies for bunch yield and its attributes, vegetative characters and bunch quality components, except fruit to bunch ratio. Fresh fruit bunch yield ranged from 167 kg·palm(-1)·year(-1) in PK1330 to 212 kg·palm(-1)·year(-1) in PK1351, with a mean yield of 192 kg·palm(-1)·year(-1). Among the progeny, PK1313 had the highest oil to bunch ratio (19.36%), due to its high mesocarp to fruit ratio, fruit to bunch ratio and low shell to fruit ratio. Among the progenies, PK1313 produced the highest oil yield of 31.4 kg·palm(-1)·year(-1), due to a high mesocarp to fruit ratio (61.2%) and a low shell to fruit ratio (30.7%), coupled with high fruit to bunch ratio (65.6%). PK1330 was found promising for selection, as it had desirable vegetative characters, including smaller petiole cross section (27.15 cm2), short rachis length (4.83 m), short palm height (1.85 m), and the lowest leaf number (164.6), as these vegetative characters are prerequisites for selecting palms for high density planting and high yield per hectare. The genetic variability among the progenies was found to be high, indicating ample scope for further breeding, followed by selection.


Asunto(s)
Arecaceae/genética , Hojas de la Planta/crecimiento & desarrollo , Selección Genética , Arecaceae/crecimiento & desarrollo , Cruzamiento , Humanos , Aceite de Palma , Aceites de Plantas
15.
ScientificWorldJournal ; 2014: 639246, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24723819

RESUMEN

Botrytis gray mold (BGM) caused by Botrytis cinerea Pers. Ex. Fr. is an extremely devastating disease of chickpea (Cicer arietinum L.) and has a regional as well as an international perspective. Unfortunately, nonchemical methods for its control are weak and ineffective. In order to identify an effective control measure, six fungicides with different modes of action were evaluated on a BGM susceptible chickpea variety BARIchhola-1 at a high BGM incidence location (Madaripur) in Bangladesh for three years (2008, 2009, and 2010). Among the six fungicides tested, one was protectant [Vondozeb 42SC, a.i. mancozeb (0.2%)], two systemic [Bavistin 50 WP, a.i. carbendazim (0.2%), and Protaf 250EC, propiconazole (0.05%)], and three combination formulations [Acrobat MZ690, dimethomorph 9% + mancozeb 60%, (0.2%); Secure 600 WG, phenomadone + mancozeb (0.2%); and Companion, mancozeb 63% + carbendazim 12% (0.2%)]. The results showed superiority of combination formulations involving both protectant and systemic fungicides over the sole application of either fungicide separately. Among the combination fungicides, Companion was most effective, resulting in the lowest disease severity (3.33 score on 1-9 scale) and the highest increase (38%) of grain yield in chickpea. Therefore, this product could be preferred over the sole application of either solo protectant or systemic fungicides to reduce yield losses and avoid fungicide resistance.


Asunto(s)
Botrytis/patogenicidad , Cicer/microbiología , Fungicidas Industriales/farmacología , Enfermedades de las Plantas/microbiología , Botrytis/efectos de los fármacos , Enfermedades de las Plantas/prevención & control
16.
ScientificWorldJournal ; 2014: 308042, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25478590

RESUMEN

High temperature tolerance is an important component of adaptation to arid and semiarid cropping environment in chili pepper. Two experiments were carried out to study the genetic variability among chili pepper for heat tolerance and morphophysiological traits and to estimate heritability and genetic advance expected from selection. There was a highly significant variation among the genotypes in response to high temperature (CMT), photosynthesis rate, plant height, disease incidence, fruit length, fruit weight, number of fruits, and yield per plant. At 5% selection intensity, high genetic advance as percent of the mean (>20%) was observed for CMT, photosynthesis rate, fruit length, fruit weight, number of fruits, and yield per plant. Similarly, high heritability (>60%) was also observed indicating the substantial effect of additive gene more than the environmental effect. Yield per plant showed strong to moderately positive correlations (r = 0.23-0.56) at phenotypic level while at genotypic level correlation coefficient ranged from 0.16 to 0.72 for CMT, plant height, fruit length, and number of fruits. Cluster analysis revealed eight groups and Group VIII recorded the highest CMT and yield. Group IV recorded 13 genotypes while Groups II, VII, and VIII recorded one each. The results showed that the availability of genetic variance could be useful for exploitation through selection for further breeding purposes.


Asunto(s)
Capsicum/genética , Frutas/genética , Variación Genética , Estrés Fisiológico/genética , Cruzamiento , Capsicum/fisiología , Frutas/fisiología , Genotipo , Calor
17.
ScientificWorldJournal ; 2014: 627916, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25003141

RESUMEN

Purslane (Portulaca oleracea L.) is an herbaceous leafy vegetable crop, comparatively more salt-tolerant than any other vegetables with high antioxidants, minerals, and vitamins. Salt-tolerant crop variety development is of importance due to inadequate cultivable land and escalating salinity together with population pressure. In this view a total of 25 purslane accessions were initially selected from 45 collected purslane accessions based on better growth performance and subjected to 5 different salinity levels, that is, 0.0, 10.0, 20.0, 30.0, and 40.0 dS m(-1) NaCl. Plant height, number of leaves, number of flowers, and dry matter contents in salt treated purslane accessions were significantly reduced (P ≤ 0.05) and the enormity of reduction increased with increasing salinity stress. Based on dry matter yield reduction, among all 25 purslane accessions 2 accessions were graded as tolerant (Ac7 and Ac9), 6 accessions were moderately tolerant (Ac3, Ac5, Ac6, Ac10, Ac11, and Ac12), 5 accessions were moderately susceptible (Ac1, Ac2, Ac4, Ac8, and Ac13), and the remaining 12 accessions were susceptible to salinity stress and discarded from further study. The selected 13 purslane accessions could assist in the identification of superior genes for salt tolerance in purslane for improving its productivity and sustainable agricultural production.


Asunto(s)
Portulaca/genética , Tolerancia a la Sal , Portulaca/efectos de los fármacos , Portulaca/crecimiento & desarrollo , Selección Genética , Cloruro de Sodio/farmacología
18.
ScientificWorldJournal ; 2014: 190531, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25431777

RESUMEN

Genetic based knowledge of different vegetative and yield traits play a major role in varietal improvement of rice. Genetic variation gives room for recombinants which are essential for the development of a new variety in any crop. Based on this background, this work was carried out to evaluate genetic diversity of derived mutant lines and establish relationships between their yield and yield components using multivariate analysis. To achieve this objective, two field trials were carried out on 45 mutant rice genotypes to evaluate their growth and yield traits. Data were taken on vegetative traits and yield and its components, while genotypic and phenotypic coefficients, variance components, expected genetic advance, and heritability were calculated. All the genotypes showed variations for vegetative traits and yield and its components. Also, there was positive relationship between the quantitative traits and the final yield with the exception of number of tillers. Finally, the evaluated genotypes were grouped into five major clusters based on the assessed traits with the aid of UPGMA dendrogram. So hybridization of group I with group V or group VI could be used to attain higher heterosis or vigour among the genotypes. Also, this evaluation could be useful in developing reliable selection indices for important agronomic traits in rice.


Asunto(s)
Variación Genética/genética , Mutación/genética , Oryza/genética , Carácter Cuantitativo Heredable , Selección Genética/genética
19.
ScientificWorldJournal ; 2014: 709614, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25140344

RESUMEN

An experiment was conducted in Field Laboratory, Department of Entomology at Bangladesh Agricultural University, Mymensingh, during 2013 to manage the mango hopper, Idioscopus clypealis L, using three chemical insecticides, Imidacloprid (0.3%), Endosulfan (0.5%), and Cypermethrin (0.4%), and natural Neem oil (3%) with three replications of each. All the treatments were significantly effective in managing mango hopper in comparison to the control. Imidacloprid showed the highest efficacy in percentage of reduction of hopper population (92.50 ± 9.02) at 72 hours after treatment in case of 2nd spray. It also showed the highest overall percentage of reduction (88.59 ± 8.64) of hopper population and less toxicity to natural enemies including green ant, spider, and lacewing of mango hopper. In case of biopesticide, azadirachtin based Neem oil was found effective against mango hopper as 48.35, 60.15, and 56.54% reduction after 24, 72, and 168 hours of spraying, respectively, which was comparable with Cypermethrin as there was no statistically significant difference after 168 hours of spray. Natural enemies were also higher after 1st and 2nd spray in case of Neem oil.


Asunto(s)
Glicéridos , Hemípteros , Insecticidas , Control de Plagas/métodos , Terpenos , Animales , Endosulfano , Imidazoles , Neonicotinoides , Nitrocompuestos , Piretrinas
20.
J Environ Biol ; 35(5): 855-64, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25204059

RESUMEN

Six weed species (Leptochola chinensis, Echinochloa crus-galli, Echinochloa colona, Jussiaea linifolia, Oryza sativa (weedy rice) and Cyperus iria) were tested for their salt tolerant traits in terms of chlorophyll, proline and mineral nutrients accumulation against different salinity levels (0, 4, 8, 16, 24, 32, and 40 dS m(-1)). Chlorophyll a, b and total chlorophyll content, proline and mineral nutrients accumulation were determined. Salt stress showed prominent effect on all the parameters investigated and there were significant variations between the all weed species. Chlorophyll content, K+, Ca(2+) and Mg(2+) ions in both shoots and roots significantly decreased; while proline and Na+ accumulation significantly increased with increasing salinity up to 40 dS m(-1). In terms of overall performance, Cyperus iria and E. crus-galliwere relatively more tolerant; E. colona and J. linifolia were tolerant; L. chinensis and O. sativa L were salt sensitive, respectively.


Asunto(s)
Clorofila/metabolismo , Oryza/metabolismo , Malezas/metabolismo , Prolina/metabolismo , Salinidad , Calcio/metabolismo , Magnesio/metabolismo , Malasia , Potasio/metabolismo , Sodio/metabolismo , Estrés Fisiológico
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