Khalid akhtar - Academia.edu (original) (raw)
Papers by Khalid akhtar
Plant Pathology, 2008
During spring 2005-06 chickpea plants (cvs Desi and Kabuli) were found to be affected by a previo... more During spring 2005-06 chickpea plants (cvs Desi and Kabuli) were found to be affected by a previously undescribed disease in Pakistan. Symptoms consisted of proliferation of branches with smaller leaflets, giving a bushy appearance to the plants. Affected plants were scattered in the field and were more easily spotted at flowering and podding time. The flowers developed abnormal green structures (phyllody) instead of normal flowers. At the time of crop maturity when the healthy plants were drying the diseased plants in the field were conspicuously green.
Chickpea (Cicer arietinum) plants of two types, kabuli and desi, showing phytoplasma disease-like... more Chickpea (Cicer arietinum) plants of two types, kabuli and desi, showing phytoplasma disease-like symptoms were observed for the first time in Pakistan during 2005. The major symptoms were floral virescence, phyllody and extensive proliferation of the branches. Light microscopy of hand-cut sections of symptomatic stems treated with Dienes' stain showed blue areas in the phloem region of diseased plants but not in apparently normal ones. Phytoplasma-like pleomorphic bodies were observed in the sieve cells of symptomatic chickpea stems by transmission electron microscopy, but not in the sieve tubes of healthy plants. Amplification from diseased plants of a 16S rDNA fragment 1800 bp in size with phytoplasma primers P1 and P7, confirmed that they hosted a phytoplasma. RFLP profiles and complete sequencing of the R16F2n/R16R2 region showed that the associated phytoplasma had 100% sequence identity in this rDNA region to 16SrII-D subgroup phytoplasmas. Chickpea phyllody disease was tr...
Caderno de Pesquisa …
Blight caused by Ascochyta rabiei is a serious disease of chickpea causing significant yield loss... more Blight caused by Ascochyta rabiei is a serious disease of chickpea causing significant yield losses in Pakistan. In order to identify sources of genetic resistance against chickpea blight, 174 chickpea germplasm lines were screened under field conditions at three locations and in glass house during 200203 to 200405. Due to rainy days between mid February to early March, the field conditions were very favorable for blight disease and even the varieties released earlier as resistant were found either susceptible or highly susceptible at all the three testing sites during the three years of study. Some lines were easily infected while others were harder to infect and had slow disease development. In our field studies none of the line was found highly resistant. However, 28 lines at NARC, 24 at AARI and 30 lines at NIAB were found resistant. Similarly 44, 47 and 30 lines displayed moderately resistant reaction to blight at NARC, AARI and NIAB, respectively. Fourteen lines viz; CMC204S, FLIP91150C x FLIP93 93C, 950035, CM149S, 950248, 950072, FLIP90144C, FLIP157C, CMC44, CH6/99, CH7/99, CH30/99, NCS2001 and CM218/01 showed moderately resistant reaction to A. rabiei through artificial inoculation in glass house and performed better (resistant) under field conditions. The genotypes identified as resistant could be used as a commercial cultivars after yield testing or in hybridization program to develop chickpea resistant cultivars.
The effect of Cotton leaf curl Burewala virus (CLCuBuV) on cotton growth, yield, photosynthetic g... more The effect of Cotton leaf curl Burewala virus (CLCuBuV) on cotton growth, yield, photosynthetic gas exchange, chlorophyll fluorescence and chlorophyll contents was studied in susceptible (CIM-496 and NIAB-111 from Gossypium hirsutum) and tolerant (Ravi from G. arboreum and Co Tiep Khac from G. herbaceum) cotton genotypes under glasshouse condition through artificial inoculation. Compared to the non-inoculated plants, the inoculated plants of susceptible genotypes showed stunted growth, reflected as significant decrease in plant height, internode length, number of leaves per plant, leaf area, number of bolls per plant, boll weight and yield per plant. Upon virus inoculation, transpiration rate decreased significantly in both susceptible genotypes while water use efficiency (WUE) was enhanced in CIM-496 compared to the non-inoculated plants. However, overall plant growth, net photosynthetic rate, leaf transpiration, stomatal conductance and WUE remained unaffected by CLCuBuVinfection in tolerant genotypes. Moreover, chlorophyll b and total chlorophyll content increased in one of the tolerant genotypes (Ravi) in response to CLCuBuV-infection while remaining unaffected in all other genotypes. Level of chlorophyll a and chlorophyll fluorescence (Fv/Fm) was not affected by CLCuBuV-infection in all genotypes. In conclusion, CLCuBuV infection adversely affected the overall plant growth and yield in susceptible genotypes while tolerant genotypes were able to maintain the growth and yield in the presence of infection. Reduced transpiration rate and increased WUE in susceptible genotypes and increased chlorophyll b and total chlorophyll content in tolerant genotypes on virus inoculation provided evidence for their significant involvement in CLCuBuV-tolerance mechanism in cotton.
Nucleus
An artificial inoculation technique for the screening of cotton germplasm against cotton leaf cur... more An artificial inoculation technique for the screening of cotton germplasm against cotton leaf curl virus (CLCuV) is described in this article. Present technique is improved shape of bottle shoot grafting method and is equally successful in field under high temperature conditions. The technique is simple and faster. Success of grafting and disease transmission was 100% in our experiments.
Pakistan Journal of Biological Sciences, 2000
ABSTRACT
Journal of Phytopathology, 2015
Whitefly transmitted begomoviruses (family Geminiviridae) are the major reason for significant yi... more Whitefly transmitted begomoviruses (family Geminiviridae) are the major reason for significant yield losses of dicotyledonous crops in tropics and subtropics. Okra (Abelmoschus esculentus) is one of the important vegetable crops, and leaf curl disease caused by geminiviruses is the most important limiting factor for its production in Pakistan. Here, we report a new species of okra-infecting begomovirus in south-eastern region of Pakistan and the name Okra enation leaf curl virus (OELCuV) complex is proposed. This okra enation leaf curl disease complex (OELCuD) in Pakistan is found to be associated with Ageratum conyzoides symptomless alphasatellite (ACon-SLA). All efforts to clone the betasatellite were unsuccessful. Comprehensive sequence analyses suggest that intermalvaceous recombination between okra and cotton-infecting begomoviruses resulted in the evolution of the new species. Surprisingly, Bhendi yellow vein mosaic virus (BY-VMV) which has not been reported previously from Pakistan is the major parent while Cotton leaf curl Multan virus (CLCuMV) acts as a distant parent of the virus. Comparative recombination analysis also reveals that okrainfecting begomoviruses from south and north-western India is causing OELCuD in the Pakistan by recombining with CLCuMV at the Rep (1964-1513 nts). Recombination is common among geminiviruses and recombining of BYVMV and CLCuMV resulted in a new species: OELCuV. To the best of our knowledge, this evolution of a new species of okra-infecting begomovirus is the first report of intermalvaceous recombination where Rep acts as the target region.
Breeding Science, 2013
Yellow mosaic disease (YMD) is one of the major diseases affecting mungbean (Vigna radiata (L.) W... more Yellow mosaic disease (YMD) is one of the major diseases affecting mungbean (Vigna radiata (L.) Wilczek). In this study, we report the mapping of the quantitative trait locus (QTL) for mungbean yellow mosaic India virus (MYMIV) resistance in mungbean. An F 8 recombinant inbred line (RIL) mapping population was generated in Thailand from a cross between NM10-12-1 (MYMIV resistance) and KPS2 (MYMIV susceptible). One hundred and twenty-two RILs and their parents were evaluated for MYMIV resistance in infested fields in India and Pakistan. A genetic linkage map was developed for the RIL population using simple sequence repeat (SSR) markers. Composite interval mapping identified five QTLs for MYMIV resistance: three QTLs for India (qYMIV1, qYMIV2 and qYMIV3) and two QTLs for Pakistan (qYMIV4 and qYMIV5). qYMIV1, qYMIV2, qYMIV3, qYMIV4 and qYMIV5 explained 9.33%, 10.61%, 12.55%, 21.93% and 6.24% of variation in disease responses, respectively. qYMIV1 and qYMIV4 appeared to be the same locus and were common to a major QTL for MYMIV resistance in India identified previously using a different resistant mungbean.
Pakistan Journal of Botany, Oct 1, 2011
Genetic control of late blight (LB) and some economic traits was assessed to identify genotypes s... more Genetic control of late blight (LB) and some economic traits was assessed to identify genotypes suitable for the development of late blight resistant hybrids in tomato. 10 F 1 hybrids were derived from crossing of 2 male sterile lines viz., TMS1 and TMS2 with 5 elite lines viz., Nagina, Riogrande, Roma, 88572 and Picdenato according to line x tester technique. Disease resistance was measured using detached leaf and whole plant assay techniques. Data were also recorded for days to maturity, number of fruit per plant, single fruit weight and yield per plant. The analysis of variance showed significant differences among crosses, lines, testers and line x tester interaction for almost all parameters. Estimate of genetic components indicated preponderance of additive type of gene action for detached leaf assay, whole plant assay, number of fruit per plant and yield per plant whereas non-additive type of gene action for days to maturity and single fruit weight. Among parents, TMS2, Nagina, Roma and Picdenato showed significant favorable general combing ability (GCA) effects for disease rating traits while TMS1 and Riogrande indicated desirable GCA effects for yield and some yield related traits. Among hybrids, TMS2 x Roma and TMS1 x Riogrande had significant specific combing ability (SCA) effects for detached and whole plant assays. However, hybrid TMS2 x Roma appeared as good combination of LB resistance as it had both parents with desirable GCA effects. All hybrids showed average type of SCA effects for yield and yield components. Genetic control of LB revealed that a multiple crossing program involving genotypes with high GCA effects would be rewarding to identify LB resistant genotypes in early generations.
International Journal of Pest Management, 2012
Cotton leaf curl virus (CLCuV) is one of the major biotic constraints of cotton production in Pak... more Cotton leaf curl virus (CLCuV) is one of the major biotic constraints of cotton production in Pakistan. Cultivation of resistant cotton genotypes is the most effective method of reducing yield losses due to CLCuV. PIM-76-8/5 is a new CL- CuV-resistant line developed through the use of induced mutation. It exhibited a highly resistant response when artificially inoculated by grafting and
Cotton leaf curl disease (CLCuD), caused by Cotton leaf curl Burewala virus (CLCuBV), is a major ... more Cotton leaf curl disease (CLCuD), caused by Cotton leaf curl Burewala virus (CLCuBV), is a major constraint for a successful production of cotton in Pakistan. All the available cotton cultivars are susceptible to this virus. Breeding for resistance to CLCuBV is the best tactic to reduce economic losses caused by this virus. In the absence of a resistant source the present investigations were carried out to find out CLCuBV-resistant genotypes by mutagenization. NIAB-111 (female parent) was crossed separately with two male parents, NIAB-999 and CIM-499. The resulting F 1 seeds were gamma irradiated. Resistance to CLCuBV was evaluated by visual symptom scoring in the f ield conditions and in nethouse/greenhouse using whitefly and graft inoculations. Out of 20 mutants tested in M 5 generation, one, mutant M-112-59/22 showed partial resistance to CLCuBV, as concluded from its low severity index (SI) of 2.3 and percent disease index (PDI) of 20. M-112-59/22 consistently expressed resistance to CLCuBV in the normal cotton growing season, while it showed a more moderate resistance response when sown late in the field, or under greenhouse conditions following inoculation by whiteflies (SI = 3.3) or graft inoculation (SI= 3.4). The yield per plant of M-112-59/22 was higher than its parents with desirable fiber characteristics even under conducive disease development conditions. These results show that mutant M-112-59/22 is a CLCuBV partially resistant source when yield, fiber quality and response to virus infection are collectively taken into consideration.
Spanish Journal of Agricultural Research, 2009
Cotton (Gossypium hirsutum L.) is an important fibre crop and a major contributor to Pakistan's f... more Cotton (Gossypium hirsutum L.) is an important fibre crop and a major contributor to Pakistan's foreign exchange earnings. It supplies 1,240 ginning mills and 453 textile units consisting of 50 composite and 403 spinning units. Approximately 68% of the country's total exports are linked directly or indirectly with cotton and it employs 40% of the total workforce in the manufacturing sector (Anon, 2004). The multiplier effect of employment in this sector is enormous and is currently fuelling the countries economy. In 1991-92, Pakistan achieved a record production of 12.8 million bales of cotton. In 1992-93 production fell to 9.
Plant Pathology, 2010
Mung bean is an important source of food for humans and animals in tropical and subtropical count... more Mung bean is an important source of food for humans and animals in tropical and subtropical countries, and is also used for green manure. During spring 2008, mung bean plants in Faisalabad, Pakistan, showed severe symptoms of phyllody, virescence and a bushy appearance. Stem, leaf and stalk phloem sections from plants with and without symptoms were examined under a light microscope (CXRII, Labomed, CA, USA) using Dienes' stain. Regularly distributed dark blue areas were observed only in the phloem cells from plants with symptoms, and not in other plant tissues nor in the phloem of healthy plants, indicating the presence of a phytoplasma. Four week-old greenhouse-potted mung bean plants were grafted, and developed phyllody symptoms 25-30 days after grafting, similar to those observed in the field, whilst no symptoms developed in non-grafted control plants.
Plant Pathology, 2008
During spring 2005-06 chickpea plants (cvs Desi and Kabuli) were found to be affected by a previo... more During spring 2005-06 chickpea plants (cvs Desi and Kabuli) were found to be affected by a previously undescribed disease in Pakistan. Symptoms consisted of proliferation of branches with smaller leaflets, giving a bushy appearance to the plants. Affected plants were scattered in the field and were more easily spotted at flowering and podding time. The flowers developed abnormal green structures (phyllody) instead of normal flowers. At the time of crop maturity when the healthy plants were drying the diseased plants in the field were conspicuously green.
Plant Pathology, 2008
During spring 2005-06 chickpea plants (cvs Desi and Kabuli) were found to be affected by a previo... more During spring 2005-06 chickpea plants (cvs Desi and Kabuli) were found to be affected by a previously undescribed disease in Pakistan. Symptoms consisted of proliferation of branches with smaller leaflets, giving a bushy appearance to the plants. Affected plants were scattered in the field and were more easily spotted at flowering and podding time. The flowers developed abnormal green structures (phyllody) instead of normal flowers. At the time of crop maturity when the healthy plants were drying the diseased plants in the field were conspicuously green.
Journal of Phytopathology, 2008
Skip to Main Content. ...
Journal of Dispersion Science and Technology, 1998
... Uniformly dispersed particles of CdCO3 were prepared by homogeneous precipitation from aqueou... more ... Uniformly dispersed particles of CdCO3 were prepared by homogeneous precipitation from aqueous solutions of cadmium sulphate and urea at the elevated temperatures. ... On calcination at 700 ◦ C, the core [CdCO3], coated ...
Plant Pathology, 2008
During spring 2005-06 chickpea plants (cvs Desi and Kabuli) were found to be affected by a previo... more During spring 2005-06 chickpea plants (cvs Desi and Kabuli) were found to be affected by a previously undescribed disease in Pakistan. Symptoms consisted of proliferation of branches with smaller leaflets, giving a bushy appearance to the plants. Affected plants were scattered in the field and were more easily spotted at flowering and podding time. The flowers developed abnormal green structures (phyllody) instead of normal flowers. At the time of crop maturity when the healthy plants were drying the diseased plants in the field were conspicuously green.
Chickpea (Cicer arietinum) plants of two types, kabuli and desi, showing phytoplasma disease-like... more Chickpea (Cicer arietinum) plants of two types, kabuli and desi, showing phytoplasma disease-like symptoms were observed for the first time in Pakistan during 2005. The major symptoms were floral virescence, phyllody and extensive proliferation of the branches. Light microscopy of hand-cut sections of symptomatic stems treated with Dienes' stain showed blue areas in the phloem region of diseased plants but not in apparently normal ones. Phytoplasma-like pleomorphic bodies were observed in the sieve cells of symptomatic chickpea stems by transmission electron microscopy, but not in the sieve tubes of healthy plants. Amplification from diseased plants of a 16S rDNA fragment 1800 bp in size with phytoplasma primers P1 and P7, confirmed that they hosted a phytoplasma. RFLP profiles and complete sequencing of the R16F2n/R16R2 region showed that the associated phytoplasma had 100% sequence identity in this rDNA region to 16SrII-D subgroup phytoplasmas. Chickpea phyllody disease was tr...
Caderno de Pesquisa …
Blight caused by Ascochyta rabiei is a serious disease of chickpea causing significant yield loss... more Blight caused by Ascochyta rabiei is a serious disease of chickpea causing significant yield losses in Pakistan. In order to identify sources of genetic resistance against chickpea blight, 174 chickpea germplasm lines were screened under field conditions at three locations and in glass house during 200203 to 200405. Due to rainy days between mid February to early March, the field conditions were very favorable for blight disease and even the varieties released earlier as resistant were found either susceptible or highly susceptible at all the three testing sites during the three years of study. Some lines were easily infected while others were harder to infect and had slow disease development. In our field studies none of the line was found highly resistant. However, 28 lines at NARC, 24 at AARI and 30 lines at NIAB were found resistant. Similarly 44, 47 and 30 lines displayed moderately resistant reaction to blight at NARC, AARI and NIAB, respectively. Fourteen lines viz; CMC204S, FLIP91150C x FLIP93 93C, 950035, CM149S, 950248, 950072, FLIP90144C, FLIP157C, CMC44, CH6/99, CH7/99, CH30/99, NCS2001 and CM218/01 showed moderately resistant reaction to A. rabiei through artificial inoculation in glass house and performed better (resistant) under field conditions. The genotypes identified as resistant could be used as a commercial cultivars after yield testing or in hybridization program to develop chickpea resistant cultivars.
The effect of Cotton leaf curl Burewala virus (CLCuBuV) on cotton growth, yield, photosynthetic g... more The effect of Cotton leaf curl Burewala virus (CLCuBuV) on cotton growth, yield, photosynthetic gas exchange, chlorophyll fluorescence and chlorophyll contents was studied in susceptible (CIM-496 and NIAB-111 from Gossypium hirsutum) and tolerant (Ravi from G. arboreum and Co Tiep Khac from G. herbaceum) cotton genotypes under glasshouse condition through artificial inoculation. Compared to the non-inoculated plants, the inoculated plants of susceptible genotypes showed stunted growth, reflected as significant decrease in plant height, internode length, number of leaves per plant, leaf area, number of bolls per plant, boll weight and yield per plant. Upon virus inoculation, transpiration rate decreased significantly in both susceptible genotypes while water use efficiency (WUE) was enhanced in CIM-496 compared to the non-inoculated plants. However, overall plant growth, net photosynthetic rate, leaf transpiration, stomatal conductance and WUE remained unaffected by CLCuBuVinfection in tolerant genotypes. Moreover, chlorophyll b and total chlorophyll content increased in one of the tolerant genotypes (Ravi) in response to CLCuBuV-infection while remaining unaffected in all other genotypes. Level of chlorophyll a and chlorophyll fluorescence (Fv/Fm) was not affected by CLCuBuV-infection in all genotypes. In conclusion, CLCuBuV infection adversely affected the overall plant growth and yield in susceptible genotypes while tolerant genotypes were able to maintain the growth and yield in the presence of infection. Reduced transpiration rate and increased WUE in susceptible genotypes and increased chlorophyll b and total chlorophyll content in tolerant genotypes on virus inoculation provided evidence for their significant involvement in CLCuBuV-tolerance mechanism in cotton.
Nucleus
An artificial inoculation technique for the screening of cotton germplasm against cotton leaf cur... more An artificial inoculation technique for the screening of cotton germplasm against cotton leaf curl virus (CLCuV) is described in this article. Present technique is improved shape of bottle shoot grafting method and is equally successful in field under high temperature conditions. The technique is simple and faster. Success of grafting and disease transmission was 100% in our experiments.
Pakistan Journal of Biological Sciences, 2000
ABSTRACT
Journal of Phytopathology, 2015
Whitefly transmitted begomoviruses (family Geminiviridae) are the major reason for significant yi... more Whitefly transmitted begomoviruses (family Geminiviridae) are the major reason for significant yield losses of dicotyledonous crops in tropics and subtropics. Okra (Abelmoschus esculentus) is one of the important vegetable crops, and leaf curl disease caused by geminiviruses is the most important limiting factor for its production in Pakistan. Here, we report a new species of okra-infecting begomovirus in south-eastern region of Pakistan and the name Okra enation leaf curl virus (OELCuV) complex is proposed. This okra enation leaf curl disease complex (OELCuD) in Pakistan is found to be associated with Ageratum conyzoides symptomless alphasatellite (ACon-SLA). All efforts to clone the betasatellite were unsuccessful. Comprehensive sequence analyses suggest that intermalvaceous recombination between okra and cotton-infecting begomoviruses resulted in the evolution of the new species. Surprisingly, Bhendi yellow vein mosaic virus (BY-VMV) which has not been reported previously from Pakistan is the major parent while Cotton leaf curl Multan virus (CLCuMV) acts as a distant parent of the virus. Comparative recombination analysis also reveals that okrainfecting begomoviruses from south and north-western India is causing OELCuD in the Pakistan by recombining with CLCuMV at the Rep (1964-1513 nts). Recombination is common among geminiviruses and recombining of BYVMV and CLCuMV resulted in a new species: OELCuV. To the best of our knowledge, this evolution of a new species of okra-infecting begomovirus is the first report of intermalvaceous recombination where Rep acts as the target region.
Breeding Science, 2013
Yellow mosaic disease (YMD) is one of the major diseases affecting mungbean (Vigna radiata (L.) W... more Yellow mosaic disease (YMD) is one of the major diseases affecting mungbean (Vigna radiata (L.) Wilczek). In this study, we report the mapping of the quantitative trait locus (QTL) for mungbean yellow mosaic India virus (MYMIV) resistance in mungbean. An F 8 recombinant inbred line (RIL) mapping population was generated in Thailand from a cross between NM10-12-1 (MYMIV resistance) and KPS2 (MYMIV susceptible). One hundred and twenty-two RILs and their parents were evaluated for MYMIV resistance in infested fields in India and Pakistan. A genetic linkage map was developed for the RIL population using simple sequence repeat (SSR) markers. Composite interval mapping identified five QTLs for MYMIV resistance: three QTLs for India (qYMIV1, qYMIV2 and qYMIV3) and two QTLs for Pakistan (qYMIV4 and qYMIV5). qYMIV1, qYMIV2, qYMIV3, qYMIV4 and qYMIV5 explained 9.33%, 10.61%, 12.55%, 21.93% and 6.24% of variation in disease responses, respectively. qYMIV1 and qYMIV4 appeared to be the same locus and were common to a major QTL for MYMIV resistance in India identified previously using a different resistant mungbean.
Pakistan Journal of Botany, Oct 1, 2011
Genetic control of late blight (LB) and some economic traits was assessed to identify genotypes s... more Genetic control of late blight (LB) and some economic traits was assessed to identify genotypes suitable for the development of late blight resistant hybrids in tomato. 10 F 1 hybrids were derived from crossing of 2 male sterile lines viz., TMS1 and TMS2 with 5 elite lines viz., Nagina, Riogrande, Roma, 88572 and Picdenato according to line x tester technique. Disease resistance was measured using detached leaf and whole plant assay techniques. Data were also recorded for days to maturity, number of fruit per plant, single fruit weight and yield per plant. The analysis of variance showed significant differences among crosses, lines, testers and line x tester interaction for almost all parameters. Estimate of genetic components indicated preponderance of additive type of gene action for detached leaf assay, whole plant assay, number of fruit per plant and yield per plant whereas non-additive type of gene action for days to maturity and single fruit weight. Among parents, TMS2, Nagina, Roma and Picdenato showed significant favorable general combing ability (GCA) effects for disease rating traits while TMS1 and Riogrande indicated desirable GCA effects for yield and some yield related traits. Among hybrids, TMS2 x Roma and TMS1 x Riogrande had significant specific combing ability (SCA) effects for detached and whole plant assays. However, hybrid TMS2 x Roma appeared as good combination of LB resistance as it had both parents with desirable GCA effects. All hybrids showed average type of SCA effects for yield and yield components. Genetic control of LB revealed that a multiple crossing program involving genotypes with high GCA effects would be rewarding to identify LB resistant genotypes in early generations.
International Journal of Pest Management, 2012
Cotton leaf curl virus (CLCuV) is one of the major biotic constraints of cotton production in Pak... more Cotton leaf curl virus (CLCuV) is one of the major biotic constraints of cotton production in Pakistan. Cultivation of resistant cotton genotypes is the most effective method of reducing yield losses due to CLCuV. PIM-76-8/5 is a new CL- CuV-resistant line developed through the use of induced mutation. It exhibited a highly resistant response when artificially inoculated by grafting and
Cotton leaf curl disease (CLCuD), caused by Cotton leaf curl Burewala virus (CLCuBV), is a major ... more Cotton leaf curl disease (CLCuD), caused by Cotton leaf curl Burewala virus (CLCuBV), is a major constraint for a successful production of cotton in Pakistan. All the available cotton cultivars are susceptible to this virus. Breeding for resistance to CLCuBV is the best tactic to reduce economic losses caused by this virus. In the absence of a resistant source the present investigations were carried out to find out CLCuBV-resistant genotypes by mutagenization. NIAB-111 (female parent) was crossed separately with two male parents, NIAB-999 and CIM-499. The resulting F 1 seeds were gamma irradiated. Resistance to CLCuBV was evaluated by visual symptom scoring in the f ield conditions and in nethouse/greenhouse using whitefly and graft inoculations. Out of 20 mutants tested in M 5 generation, one, mutant M-112-59/22 showed partial resistance to CLCuBV, as concluded from its low severity index (SI) of 2.3 and percent disease index (PDI) of 20. M-112-59/22 consistently expressed resistance to CLCuBV in the normal cotton growing season, while it showed a more moderate resistance response when sown late in the field, or under greenhouse conditions following inoculation by whiteflies (SI = 3.3) or graft inoculation (SI= 3.4). The yield per plant of M-112-59/22 was higher than its parents with desirable fiber characteristics even under conducive disease development conditions. These results show that mutant M-112-59/22 is a CLCuBV partially resistant source when yield, fiber quality and response to virus infection are collectively taken into consideration.
Spanish Journal of Agricultural Research, 2009
Cotton (Gossypium hirsutum L.) is an important fibre crop and a major contributor to Pakistan's f... more Cotton (Gossypium hirsutum L.) is an important fibre crop and a major contributor to Pakistan's foreign exchange earnings. It supplies 1,240 ginning mills and 453 textile units consisting of 50 composite and 403 spinning units. Approximately 68% of the country's total exports are linked directly or indirectly with cotton and it employs 40% of the total workforce in the manufacturing sector (Anon, 2004). The multiplier effect of employment in this sector is enormous and is currently fuelling the countries economy. In 1991-92, Pakistan achieved a record production of 12.8 million bales of cotton. In 1992-93 production fell to 9.
Plant Pathology, 2010
Mung bean is an important source of food for humans and animals in tropical and subtropical count... more Mung bean is an important source of food for humans and animals in tropical and subtropical countries, and is also used for green manure. During spring 2008, mung bean plants in Faisalabad, Pakistan, showed severe symptoms of phyllody, virescence and a bushy appearance. Stem, leaf and stalk phloem sections from plants with and without symptoms were examined under a light microscope (CXRII, Labomed, CA, USA) using Dienes' stain. Regularly distributed dark blue areas were observed only in the phloem cells from plants with symptoms, and not in other plant tissues nor in the phloem of healthy plants, indicating the presence of a phytoplasma. Four week-old greenhouse-potted mung bean plants were grafted, and developed phyllody symptoms 25-30 days after grafting, similar to those observed in the field, whilst no symptoms developed in non-grafted control plants.
Plant Pathology, 2008
During spring 2005-06 chickpea plants (cvs Desi and Kabuli) were found to be affected by a previo... more During spring 2005-06 chickpea plants (cvs Desi and Kabuli) were found to be affected by a previously undescribed disease in Pakistan. Symptoms consisted of proliferation of branches with smaller leaflets, giving a bushy appearance to the plants. Affected plants were scattered in the field and were more easily spotted at flowering and podding time. The flowers developed abnormal green structures (phyllody) instead of normal flowers. At the time of crop maturity when the healthy plants were drying the diseased plants in the field were conspicuously green.
Plant Pathology, 2008
During spring 2005-06 chickpea plants (cvs Desi and Kabuli) were found to be affected by a previo... more During spring 2005-06 chickpea plants (cvs Desi and Kabuli) were found to be affected by a previously undescribed disease in Pakistan. Symptoms consisted of proliferation of branches with smaller leaflets, giving a bushy appearance to the plants. Affected plants were scattered in the field and were more easily spotted at flowering and podding time. The flowers developed abnormal green structures (phyllody) instead of normal flowers. At the time of crop maturity when the healthy plants were drying the diseased plants in the field were conspicuously green.
Journal of Phytopathology, 2008
Skip to Main Content. ...
Journal of Dispersion Science and Technology, 1998
... Uniformly dispersed particles of CdCO3 were prepared by homogeneous precipitation from aqueou... more ... Uniformly dispersed particles of CdCO3 were prepared by homogeneous precipitation from aqueous solutions of cadmium sulphate and urea at the elevated temperatures. ... On calcination at 700 ◦ C, the core [CdCO3], coated ...