Genomic characterization of Puccinia triticina using molecular marker technology / Caracterização genômica de Puccinia triticina usando tecnologia de marcadores moleculares

Leaf rust, caused by Puccinia triticina, is the most common rust disease of wheat. The fungus is an obligate parasite capable of producing infectious urediniospores. To study the genetic structure of the leaf rust population 20 RAPD primers were evaluated on 15 isolates samples collected in Pakistan. A total of 105 RAPD fragments were amplified with an average of 7 fragments per primer. The number of amplified fragments varied from 1 to 12. GL Decamer L-07 and GL Decamer L-01 amplified the highest number of bands (twelve) and primer GL Decamer A-03 amplified the lowest number of bands i.e one. Results showed that almost all investigated isolates were genetically different that confirms high genetic diversity within the leaf rust population. Rust spores can follow the migration pattern in short and long distances to neighbor areas. Results indicated that the greatest variability was revealed by 74.9% of genetic differentiation within leaf rust populations. These results suggested that each population was not completely identical and high gene flow has occurred among the leaf rust population of different areas. The highest differentiation and genetic distance among the Pakistani leaf rust populations were detected between the leaf rust population in NARC isolate (NARC-4) and AARI-11and the highest similarity was observed between NARC isolates (NARC-4) and (NARC-5). The present study showed the leaf rust population in Pakistan is highly dynamic and variable.

A ferrugem da folha, causada por Puccinia triticina, é a ferrugem mais comum do trigo. O fungo é um parasita obrigatório, capaz de produzir urediniósporos infecciosos. Para estudar a estrutura genética da população de ferrugem da folha, 20 primers RAPD foram avaliados em 15 amostras de isolados coletadas no Paquistão. Um total de 105 fragmentos RAPD foram amplificados com uma média de 7 fragmentos por primer. O número de fragmentos amplificados variou de 1 a 12. GL Decamer L-07 e GL Decamer L-01 amplificaram o maior número de bandas (doze), e o primer GL Decamer A-03 amplificou o menor número de bandas, ou seja, um. Os resultados mostraram que quase todos os isolados investigados eram geneticamente diferentes, o que confirma a alta diversidade genética na população de ferrugem da folha. Os esporos de ferrugem podem seguir o padrão de migração em distâncias curtas e longas para áreas vizinhas. Os resultados indicaram que a maior variabilidade foi revelada por 74,9% da diferenciação genética nas populações de ferrugem. Esses resultados sugeriram que cada população não era completamente idêntica e um alto fluxo gênico ocorreu entre a população de ferrugem da folha de diferentes áreas. A maior diferenciação e distância genética entre as populações de ferrugem da folha do Paquistão foram detectadas entre a população de ferrugem da folha no isolado NARC (NARC-4) e AARI-11 e a maior similaridade foi observada entre os isolados NARC (NARC-4) e (NARC-5). O presente estudo mostrou que a população de ferrugem da folha no Paquistão é altamente dinâmica e variável.

Characterization of the species of genus Physa on the basis of typological species concept from Central Punjab / Caracterização das espécies do gênero Physa com base no conceito tipológico de espécie do Punjab Central

Physids belong to Class Gastropoda; Phylum Mollusca have important position in food web and act as bio indicators, pests and intermediate host. Being resistant these are called cockroaches of malacology. Physid snails were collected from different water bodies of Faisalabad (Punjab) and were identified up to species using morphological markers. The morphometry of the specimens was carried out with the help of a digital Vernier caliper in millimeters (mm) using linear measurement of shell characters. Linear regression analysis of the AL/SW ratio vs AL and SL/SW ratiovs AL indicated that allometric growth exists only in Physa acuta when compared with P.gyrina and P. fontinalis. This study will lead to assess the status of the Physid species in Central Punjab. The Principal component analysis shows that the Component 1 (Shell Length) and component 2 (Shell Width) are the most prolific components and nearly 80 percent of the identification. The distance between P. acuta and P. fontinalis is 5.4699, P. acuta and P. gyrina is 7.6411, P. fontinalis and P. gyrina is 16.6080 showing that P. acuta resembles with P. fontinalis, and both these specimens donot resemble with P. gyrina. P.acuta is an invasive species and shows bioactivity making it a potent candidate for bioactive substances.

Os físidos pertencem à classe Gastropoda; o filo Mollusca possui importante posição na teia alimentar e atua como bioindicador, praga e hospedeiro intermediário. Por serem resistentes, são chamadas baratas de malacologia. Os caramujos físidos foram coletados em diferentes corpos d’água de Faisalabad (Punjab) e identificados até as espécies por meio de marcadores morfológicos. A morfometria dos corpos de prova foi realizada com auxílio de paquímetro digital Vernier em milímetros (mm) por meio de medida linear dos caracteres da casca. A análise de regressão linear da razão AL / SW vs. AL e razão SL / SW vs. AL indicou que o crescimento alométrico existe apenas em Physa acuta quando comparado com P. gyrina e P. fontinalis. Este estudo levará a avaliar a situação das espécies de físido no Punjab Central. A análise do componente principal mostra que o componente 1 (comprimento da casca) e o componente 2 (largura da casca) são os componentes mais prolíficos e quase 80% da identificação. A distância entre P. acuta e P. fontinalis é 5,4699, P. acuta e P. gyrina é 7,6411, P. fontinalis e P. gyrina é 16,6080, mostrando que P. acuta se assemelha a P. fontinalis, e ambos os espécimes não se parecem com P. gyrina. P. acuta é uma espécie invasora e apresenta bioatividade, tornando-se uma candidata potente para substâncias bioativas.

Molecular Phylogenetics of Physa acuta (Pulmonata: Basommatophora): an invasive species in Central Punjab Pakistan / Molecular Phylogenetics of Physa acuta (Pulmonata: Basommatophora): uma espécie invasora no centro de Punjab, Paquistão

Physids belong to Class Gastropoda; belong to Phylum Mollusca and being bioindicators, intermediate hosts of parasites and pests hold a key position in the ecosystem. There are three species of Genus Physa i.e. P. fontinalis, Physa acuta and P. gyrina water bodies of Central Punjab and were characterized on the basis of molecular markers High level of genetic diversity was revealed by polymorphic RAPD, however SSR markers were not amplified. The multivariate analysis revealed polymorphism ranging from 9.09 percent to 50 percent among the three Physid species. Total number of 79 loci were observed for the three species under study and 24 loci were observed to be polymorphic. These RAPD fragment(s) can be developed into co dominant markers (SCAR) by cloning and can be further sequenced for the development of the Physa species specific markers to identify the introduced and native species in Pakistan.

Os físidos pertencem à classe Gastropoda; pertencem ao filo Mollusca e, sendo bioindicadores, hospedeiros intermediários de parasitas e pragas, ocupam uma posição-chave no ecossistema. Existem três espécies do gênero Physa, ou seja, P. fontinalis, Physa acuta e P. gyrina em corpos d’água do Punjab Central e foram caracterizadas com base em marcadores moleculares. Alto nível de diversidade genética foi revelado por RAPD polimórfico, no entanto os marcadores SSR não foram amplificados. A análise multivariada revelou polimorfismo variando de 9,09% a 50% entre as três espécies de Physid. Um número total de 79 loci foi observado para as três espécies em estudo e 24 loci foram observados como polimórficos. Esses fragmentos RAPD podem ser desenvolvidos em marcadores codominantes (SCAR) por clonagem e podem ser posteriormente sequenciados para o desenvolvimento de marcadores específicos da espécie Physa para identificar as espécies introduzidas e nativas no Paquistão.

Characterization of the species of genus Physa on the basis of typological species concept from Central Punjab

Abstract Physids belong to Class Gastropoda; Phylum Mollusca have important position in food web and act as bio indicators, pests and intermediate host. Being resistant these are called cockroaches of malacology. Physid snails were collected from different water bodies of Faisalabad (Punjab) and were identified up to species using morphological markers. The morphometry of the specimens was carried out with the help of a digital Vernier caliper in millimeters (mm) using linear measurement of shell characters. Linear regression analysis of the AL/SW ratio vs AL and SL/SW ratio vs AL indicated that allometric growth exists only in Physa acuta when compared with P.gyrina and P. fontinalis. This study will lead to assess the status of the Physid species in Central Punjab. The Principal component analysis shows that the Component 1 (Shell Length) and component 2 (Shell Width) are the most prolific components and nearly 80 percent of the identification. The distance between P. acuta and P. fontinalis is 5.4699, P. acuta and P. gyrina is 7.6411, P. fontinalis and P. gyrina is 16.6080 showing that P. acuta resembles with P. fontinalis, and both these specimens donot resemble with P. gyrina. P.acuta is an invasive species and shows bioactivity making it a potent candidate for bioactive substances.

Resumo Os físidos pertencem à classe Gastropoda; o filo Mollusca possui importante posição na teia alimentar e atua como bioindicador, praga e hospedeiro intermediário. Por serem resistentes, são chamadas baratas de malacologia. Os caramujos físidos foram coletados em diferentes corpos dágua de Faisalabad (Punjab) e identificados até as espécies por meio de marcadores morfológicos. A morfometria dos corpos de prova foi realizada com auxílio de paquímetro digital Vernier em milímetros (mm) por meio de medida linear dos caracteres da casca. A análise de regressão linear da razão AL / SW vs. AL e razão SL / SW vs. AL indicou que o crescimento alométrico existe apenas em Physa acuta quando comparado com P. gyrina e P. fontinalis. Este estudo levará a avaliar a situação das espécies de físido no Punjab Central. A análise do componente principal mostra que o componente 1 (comprimento da casca) e o componente 2 (largura da casca) são os componentes mais prolíficos e quase 80% da identificação. A distância entre P. acuta e P. fontinalis é 5,4699, P. acuta e P. gyrina é 7,6411, P. fontinalis e P. gyrina é 16,6080, mostrando que P. acuta se assemelha a P. fontinalis, e ambos os espécimes não se parecem com P. gyrina. P. acuta é uma espécie invasora e apresenta bioatividade, tornando-se uma candidata potente para substâncias bioativas.

Molecular Phylogenetics of Physa acuta (Pulmonata: Basommatophora): an Invasive species in Central Punjab Pakistan

Abstract Physids belong to Class Gastropoda; belong to Phylum Mollusca and being bioindicators, intermediate hosts of parasites and pests hold a key position in the ecosystem. There are three species of Genus Physa i.e. P. fontinalis, Physa acuta and P. gyrina water bodies of Central Punjab and were characterized on the basis of molecular markers High level of genetic diversity was revealed by polymorphic RAPD, however SSR markers were not amplified. The multivariate analysis revealed polymorphism ranging from 9.09 percent to 50 percent among the three Physid species. Total number of 79 loci were observed for the three species under study and 24 loci were observed to be polymorphic. These RAPD fragment(s) can be developed into co dominant markers (SCAR) by cloning and can be further sequenced for the development of the Physa species specific markers to identify the introduced and native species in Pakistan.

Resumo Os físidos pertencem à classe Gastropoda; pertencem ao filo Mollusca e, sendo bioindicadores, hospedeiros intermediários de parasitas e pragas, ocupam uma posição-chave no ecossistema. Existem três espécies do gênero Physa, ou seja, P. fontinalis, Physa acuta e P. gyrina em corpos dágua do Punjab Central e foram caracterizadas com base em marcadores moleculares. Alto nível de diversidade genética foi revelado por RAPD polimórfico, no entanto os marcadores SSR não foram amplificados. A análise multivariada revelou polimorfismo variando de 9,09% a 50% entre as três espécies de Physid. Um número total de 79 loci foi observado para as três espécies em estudo e 24 loci foram observados como polimórficos. Esses fragmentos RAPD podem ser desenvolvidos em marcadores codominantes (SCAR) por clonagem e podem ser posteriormente sequenciados para o desenvolvimento de marcadores específicos da espécie Physa para identificar as espécies introduzidas e nativas no Paquistão.

Characterization of the species of genus Physa on the basis of typological species concept from Central Punjab / Caracterização das espécies do gênero Physa com base no conceito tipológico de espécie do Punjab Central

Abstract Physids belong to Class Gastropoda; Phylum Mollusca have important position in food web and act as bio indicators, pests and intermediate host. Being resistant these are called cockroaches of malacology. Physid snails were collected from different water bodies of Faisalabad (Punjab) and were identified up to species using morphological markers. The morphometry of the specimens was carried out with the help of a digital Vernier caliper in millimeters (mm) using linear measurement of shell characters. Linear regression analysis of the AL/SW ratio vs AL and SL/SW ratio vs AL indicated that allometric growth exists only in Physa acuta when compared with P.gyrina and P. fontinalis. This study will lead to assess the status of the Physid species in Central Punjab. The Principal component analysis shows that the Component 1 (Shell Length) and component 2 (Shell Width) are the most prolific components and nearly 80 percent of the identification. The distance between P. acuta and P. fontinalis is 5.4699, P. acuta and P. gyrina is 7.6411, P. fontinalis and P. gyrina is 16.6080 showing that P. acuta resembles with P. fontinalis, and both these specimens donot resemble with P. gyrina. P.acuta is an invasive species and shows bioactivity making it a potent candidate for bioactive substances.

Resumo Os físidos pertencem à classe Gastropoda; o filo Mollusca possui importante posição na teia alimentar e atua como bioindicador, praga e hospedeiro intermediário. Por serem resistentes, são chamadas baratas de malacologia. Os caramujos físidos foram coletados em diferentes corpos d'água de Faisalabad (Punjab) e identificados até as espécies por meio de marcadores morfológicos. A morfometria dos corpos de prova foi realizada com auxílio de paquímetro digital Vernier em milímetros (mm) por meio de medida linear dos caracteres da casca. A análise de regressão linear da razão AL / SW vs. AL e razão SL / SW vs. AL indicou que o crescimento alométrico existe apenas em Physa acuta quando comparado com P. gyrina e P. fontinalis. Este estudo levará a avaliar a situação das espécies de físido no Punjab Central. A análise do componente principal mostra que o componente 1 (comprimento da casca) e o componente 2 (largura da casca) são os componentes mais prolíficos e quase 80% da identificação. A distância entre P. acuta e P. fontinalis é 5,4699, P. acuta e P. gyrina é 7,6411, P. fontinalis e P. gyrina é 16,6080, mostrando que P. acuta se assemelha a P. fontinalis, e ambos os espécimes não se parecem com P. gyrina. P. acuta é uma espécie invasora e apresenta bioatividade, tornando-se uma candidata potente para substâncias bioativas.

Molecular Phylogenetics of Physa acuta (Pulmonata: Basommatophora): an Invasive species in Central Punjab Pakistan / Molecular Phylogenetics of Physa acuta (Pulmonata: Basommatophora): uma espécie invasora no centro de Punjab, Paquistão

Abstract Physids belong to Class Gastropoda; belong to Phylum Mollusca and being bioindicators, intermediate hosts of parasites and pests hold a key position in the ecosystem. There are three species of Genus Physa i.e. P. fontinalis, Physa acuta and P. gyrina water bodies of Central Punjab and were characterized on the basis of molecular markers High level of genetic diversity was revealed by polymorphic RAPD, however SSR markers were not amplified. The multivariate analysis revealed polymorphism ranging from 9.09 percent to 50 percent among the three Physid species. Total number of 79 loci were observed for the three species under study and 24 loci were observed to be polymorphic. These RAPD fragment(s) can be developed into co dominant markers (SCAR) by cloning and can be further sequenced for the development of the Physa species specific markers to identify the introduced and native species in Pakistan.

Resumo Os físidos pertencem à classe Gastropoda; pertencem ao filo Mollusca e, sendo bioindicadores, hospedeiros intermediários de parasitas e pragas, ocupam uma posição-chave no ecossistema. Existem três espécies do gênero Physa, ou seja, P. fontinalis, Physa acuta e P. gyrina em corpos d'água do Punjab Central e foram caracterizadas com base em marcadores moleculares. Alto nível de diversidade genética foi revelado por RAPD polimórfico, no entanto os marcadores SSR não foram amplificados. A análise multivariada revelou polimorfismo variando de 9,09% a 50% entre as três espécies de Physid. Um número total de 79 loci foi observado para as três espécies em estudo e 24 loci foram observados como polimórficos. Esses fragmentos RAPD podem ser desenvolvidos em marcadores codominantes (SCAR) por clonagem e podem ser posteriormente sequenciados para o desenvolvimento de marcadores específicos da espécie Physa para identificar as espécies introduzidas e nativas no Paquistão.

Genomic characterization of Puccinia triticina using molecular marker technology.

Leaf rust, caused by Puccinia triticina, is the most common rust disease of wheat. The fungus is an obligate parasite capable of producing infectious urediniospores. To study the genetic structure of the leaf rust population 20 RAPD primers were evaluated on 15 isolates samples collected in Pakistan. A total of 105 RAPD fragments were amplified with an average of 7 fragments per primer. The number of amplified fragments varied from 1 to 12. GL Decamer L-07 and GL Decamer L-01 amplified the highest number of bands (twelve) and primer GL Decamer A-03 amplified the lowest number of bands i.e one. Results showed that almost all investigated isolates were genetically different that confirms high genetic diversity within the leaf rust population. Rust spores can follow the migration pattern in short and long distances to neighbor areas. Results indicated that the greatest variability was revealed by 74.9% of genetic differentiation within leaf rust populations. These results suggested that each population was not completely identical and high gene flow has occurred among the leaf rust population of different areas. The highest differentiation and genetic distance among the Pakistani leaf rust populations were detected between the leaf rust population in NARC isolate (NARC-4) and AARI-11and the highest similarity was observed between NARC isolates (NARC-4) and (NARC-5). The present study showed the leaf rust population in Pakistan is highly dynamic and variable.

Characterization of the species of genus Physa on the basis of typological species concept from Central Punjab.

Physids belong to Class Gastropoda; Phylum Mollusca have important position in food web and act as bio indicators, pests and intermediate host. Being resistant these are called cockroaches of malacology. Physid snails were collected from different water bodies of Faisalabad (Punjab) and were identified up to species using morphological markers. The morphometry of the specimens was carried out with the help of a digital Vernier caliper in millimeters (mm) using linear measurement of shell characters. Linear regression analysis of the AL/SW ratio vs AL and SL/SW ratio vs AL indicated that allometric growth exists only in Physa acuta when compared with P.gyrina and P. fontinalis. This study will lead to assess the status of the Physid species in Central Punjab. The Principal component analysis shows that the Component 1 (Shell Length) and component 2 (Shell Width) are the most prolific components and nearly 80 percent of the identification. The distance between P. acuta and P. fontinalis is 5.4699, P. acuta and P. gyrina is 7.6411, P. fontinalis and P. gyrina is 16.6080 showing that P. acuta resembles with P. fontinalis, and both these specimens donot resemble with P. gyrina. P.acuta is an invasive species and shows bioactivity making it a potent candidate for bioactive substances.

Molecular Phylogenetics of Physa acuta (Pulmonata: Basommatophora): an Invasive species in Central Punjab Pakistan.

Physids belong to Class Gastropoda; belong to Phylum Mollusca and being bioindicators, intermediate hosts of parasites and pests hold a key position in the ecosystem. There are three species of Genus Physa i.e. P. fontinalis, Physa acuta and P. gyrina water bodies of Central Punjab and were characterized on the basis of molecular markers High level of genetic diversity was revealed by polymorphic RAPD, however SSR markers were not amplified. The multivariate analysis revealed polymorphism ranging from 9.09 percent to 50 percent among the three Physid species. Total number of 79 loci were observed for the three species under study and 24 loci were observed to be polymorphic. These RAPD fragment(s) can be developed into co dominant markers (SCAR) by cloning and can be further sequenced for the development of the Physa species specific markers to identify the introduced and native species in Pakistan.

Assessment of allelic diversity among drought-resistant cotton genotypes using microsatellite markers.

Drought, in conjunction with high temperature, is an important environmental constraint to cotton production. Development of cotton varieties with increased tolerance against adverse environmental conditions has been proposed as effective strategy for ensuring reliable yields. In the present study, 30 simple sequence repeat (SSR) primers were used to estimate genetic divergence among 22 cotton genotypes for drought stress tolerance. Genetic diversity is a prerequisite for developing drought resistant cotton genotypes. Eleven SSR primers out of 30 were able to discriminate among the cotton genotypes, implying that 37% of the primers were informative. In total, 41 alleles were detected, with an average of 3.72 alleles per primer. The number of alleles per locus ranged from one (JESPR-284) to six (JESSPR-302), and the allelic diversity in the experimental material was 0.40. Genetic similarity coefficients ranged from 0.87-1.00. The result of principal component analysis confirmed the clustering of 21 cotton genotypes in two groups leaving one genotype (CIM-109) ungrouped. Overall, genetic diversity among the 22 cotton genotypes was low. More polymorphic SSR markers are needed to explore the workable genetic variation among the screened cotton genotypes in future studies.

An insight in the genetic control and interrelationship of some quality traits in Brassica napus.

A study on three leading lines (KN-256, KN-257, and KN-258) of Brassica napus and an approved variety, Punjab-Sarson, was conducted to gain insight into the genetic control of some quality traits using generation mean analysis. Our results showed that additive gene action predominated in the inheritance of oil content and erucic acid in cross KN-256 x KN-257 and in that of glucosinolates in KN-258 x Punjab-Sarson, indicating that these traits may be improved through selection in early segregating generations. Negative dominance can be exploited through heterosis breeding for the development of lines with low glucosinolates in cross KN-256 x KN-257. Protein content and oleic acid in cross KN-256 x KN-257, and oil content, protein content, and erucic acid in cross KN-258 x Punjab-Sarson depicted non-additive gene action and require further improvement in the later segregating generations. Most of the traits displayed high heritability estimates; glucosinolate content in both the crosses and erucic acid in cross KN- 258 x Punjab-Sarson also displayed high genetic advance, reflecting improvement of the trait in the early segregating generations. All the quality traits were positively correlated with oil content and with one another at both (genotypic and phenotypic) levels in KN-256 x KN-257. Negative correlation was observed between glucosinolate and erucic acid, oleic acid and erucic acid, and linolenic acid and oil content in cross KN-258 x Punjab-Sarson. Thus, gene action changed with the material, and cross KN-258 x Punjab-Sarson carried favorable combinations compared to KN-256 x KN-257.

Identification and authentication of Rosa species through development of species-specific SCAR marker(s).

Roses (Rosa indica) belong to one of the most crucial groups of plants in the floriculture industry. Rosa species have special fragrances of interest to the perfume and pharmaceutical industries. The genetic diversity of plants based on morphological characteristics is difficult to measure under natural conditions due to the influence of environmental factors, which is why a reliable fingerprinting method was developed to overcome this problem. The development of molecular markers will enable the identification of Rosa species. In the present study, randomly amplified polymorphic DNA (RAPD) analysis was done on four Rosa species, Rosa gruss-an-teplitz (Surkha), Rosa bourboniana, Rosa centifolia, and Rosa damascena. A polymorphic RAPD fragment of 391 bp was detected in R. bourboniana, which was cloned, purified, sequenced, and used to design a pair of species-specific sequence-characterized amplified region (SCAR) primers (forward and reverse). These SCAR primers were used to amplify the specific regions of the rose genome. These PCR amplifications with specific primers are less sensitive to reaction conditions, and due to their high reproducibility, these species-specific SCAR primers can be used for marker-assisted selection and identification of Rosa species.

Development of a species-specific sequence-characterized amplified region marker for roses.

DNA fingerprints of four rose species, Rosa centifolia, R. Gruss-an-Teplitz, R. bourboniana, and R. damascena, were developed using RAPD-PCR. We identified a unique polymorphic band in R. centifolia. This 762-bp fragment was produced by the random primer GLI-2. The fragment was eluted and directly cloned in a TA cloning vector, pTZ57R/T. Digestion of the plasmid with EcoRI confirmed the cloning of GLI-2(762) in pTZ57R/T. A second enzyme, PstI, used in combination with EcoRI, gave complete digestion of the plasmid, and the 762-bp fragment was confirmed on the gel. Subsequently, the polymorphic amplicon was sequenced with an AB1 373 DNA sequencer system using the PRISM(TM) Ready Reaction DyeDeoxy(TM) Terminator Cycle Sequencing kit. After sequencing, specific primers (23 bp long) were designed based on the sequence of the flanking regions of the original RAPD fragment. These primers will effectively allow fingerprinting for the identification of R. centifolia species. In essence, we developed an SCAR marker to authenticate the identity of R. centifolia species and to distinguish it from its substitutes. Such techniques are required not only to complement conventional parameters in creating the passport data of commercial and medicinal products of rose, but also for routine quality control in commercial and government rosaries and rose nurseries.

Molecular characterization of urdbean (Vigna mungo) germplasm related to resistance against urdbean leaf crinkle virus.

Urdbean (Vigna mungo) is an important pulse crop grown worldwide. Urdbean leaf crinkle virus (ULCV) is a pathogen of urdbean found in Pakistan that causes huge losses in yield. Forty urdbean varieties/lines were screened against the virus under field conditions during spring season 2009. None of the lines appeared to be highly resistant or resistant. On the basis of a 0-5 disease rating scale and disease severity index, genotypes varied significantly in their reaction to ULCV. Four lines (M-6206, IAM-382-15, IAM-133, and Mash-1) were moderately resistant, eight were rated as moderately susceptible, and 21 as susceptible; the remaining seven lines were highly susceptible. RAPD analyses revealed an extensive amount of variation, which could be used for cultivar identification. Genetic differentiation among urdbean genotypes was similar to the field screening data. The varieties 6065-3 and 6206 were highly susceptible and moderately resistant, respectively, to ULCV under field conditions, confirmed by the RAPD analysis. These varieties were the most diverse varieties in the similarity matrix (67.2%), while the varieties IAM-382-9 and 07M003 were the most similar (98.4%). This information will help in the recognition of available resistant germplasms that can resist this disease and will be utilized for urdbean improvement in Pakistan.

Estimation of genetic distance based on RAPDs between 11 cotton accessions varying in heat tolerance.

The genetic distance of 11 cotton genotypes varying in heat tolerance was studied using RAPD markers. Fifty-three random decamer primers were used for the estimation of genetic distance. Among the 53 RAPD primers, which were custom synthesized by GeneLink Inc., UK, 32 were polymorphic and 21 were monomorphic. The 32 polymorphic primers produced 273 fragments, with a mean of 8.3 fragments per primer. The number of polymorphic bands produced in the 11 cotton accessions ranged from 1 to 31. Primer GLC-20 produced 31 polymorphic bands, while two primers, GLB-5 and GLC-12, produced one polymorphic band each. A range of 88.89 to 42.48% genetic similarity was observed among the 11 cotton accessions. The highest genetic similarity was observed between FH-945 and BH-160 (88.89%), whereas the lowest value was found between NIAB-801/2 and FH-945 (42.48%). Unique amplification profiles were produced by most of the cultivars; the differences were sufficient to distinguish them from other genotypes. This confirms the efficacy of RAPD markers for the identification of plant genotypes. An accumulative analysis of amplified products generated by RAPDs was sufficient to assess the genetic diversity among the genotypes. This information should be helpful for formulating breeding and genome mapping programs.

Genetic diversity of chickpea (Cicer arietinum L.) germplasm in Pakistan as revealed by RAPD analysis.

Genetic diversity analysis of chickpea germplasm can provide practical information for the selection of parental material and thus assist in planning breeding strategies. Chickpea seed is a good source of carbohydrates and proteins, constituting 80% of the total dry seed weight. Released cultivars and advanced lines of 30 chickpea genotypes were subjected to RAPD analysis for assessment of genetic diversity. We used 16 RAPD primers. Amplification of genomic DNA of the 30 genotypes yielded 62 fragments that could be scored. The number of amplification products produced per primer varied from two to four, with a mean of three bands. The total number of bands amplified by 16 anchored primers varied from 16 to 34. The primer GLK-15 produced the largest number (N = 4) of fragments, whereas primers GLK-19 and GLD-19 produced the smallest number (N = 1) of fragments. The single band produced by the GTGTGCCCCA primer in the PB-2000 and 07005 genotypes may be attributed to temperature tolerance phenotypes.

Biodiversity in the sorghum (Sorghum bicolor L. Moench) germplasm of Pakistan.

Sorghum ranks fifth in worldwide economic importance among cereal crops and is one of the most important summer annual grasses of Pakistan. As it is a very diverse crop, sorghum genetic fingerprinting requires an efficient marker system. We estimated genetic divergence among 29 sorghum (Sorghum bicolor) genotypes, including approved varieties and local and exotic lines collected from different ecological regions of Pakistan, using random amplified polymorphic DNA (RAPD) markers. A total of 125 RAPD loci, with an average of 66 loci per genotype, were used to calculate genetic divergence among these genotypes, of which 119 were polymorphic, showing 95% overall polymorphism. Genetic similarity ranged from 0.36 to 0.92, indicating a relatively broad genetic base. RAPD analysis revealed maximum similarity between the Indian III and K-A-113 sorghum genotypes (both exotic lines), while the F-601 and F-606 were observed to be the most diverse genotypes. Mean band frequency revealed by these RAPD primers ranged from 0.17 to 0.56, with an average of 0.36. The data presented here support the findings that RAPDs can be effectively used for studying genetic diversity in sorghum.

Estimation of genetic distance between 10 maize accessions with varying response to different levels of soil moisture.

Ten maize accessions (NC-9, A50-2, M-14, B-42, NC-3, T-7, N-48-1, B-34, USSR, and WFTMS) were studied to estimate the genetic distance on molecular level by random amplified polymorphic DNA. These accessions were selected on the basis of their variable responses against different levels of moisture. Twenty-five primers were used to test genetic diversity, of which 14 were observed to be polymorphic. Ninety-three loci were amplified; among these, 77 showed polymorphism and the other 16 were monomorphic. Primers A-13 and C-02 gave the most polymorphic bands, while primers A-01 and C-06 gave the fewest polymorphic bands. The genetic similarities of the 10 maize accessions ranged from 82.8 to 54.8%. Accessions USSR and WFTMS showed greatest similarity, and accessions M-14 and B-42 were found more dissimilar than the other accessions. On the basis of cluster analysis, these 10 accessions were classified in two major groups, A and B, and than further divided into sub-groups. The cluster analysis showed that accessions in the same group as well as in the sub-groups were similar in their physical and morphological characters, since the characters are controlled genetically.

Study of genetic divergence among wheat genotypes through random amplified polymorphic DNA.

The degree of genetic divergence was estimated in seven wheat genotypes, six exotic genotypes and one local variety, through random amplified polymorphic DNA methodology. A total of 112 DNA fragments were generated by the 15 random primers, with an average of about 7.4 bands per primer. Among the 112, 50 fragments showed polymorphism among the seven wheat genotypes. Nei and Li's similarity matrix ranged from 86.2 to 93.0%, which indicated a narrow genetic base among the genotypes. The maximum similarity, 93.0%, was observed between 12WLRG/1-12 and WL-43. The local variety, Chenab-70, showed the lowest similarity with the exotic types. We conclude that random amplified polymorphic DNA analysis can be used for the characterization and grouping of wheat genotypes; these results will be helpful in our wheat breeding program.