[Show abstract][Hide abstract]ABSTRACT: In present study, virulence and aggressiveness of seven Xanthomonas oryzae hypersensitive isolates, (Xoo 20, Xoo 36, Xoo 51, Xoo 65, Xoo 74, Xoo 99 and Xoo 105) were tested on seven rice varieties (Basmati 385, IRRI 26, Basmati 386, Dilroosh 97, JP 5, Super Basmati, Basmati 2000 and Ks 282), through detached leaf, glass house and field assays Xoo 99 showed most aggressive reaction on detached leaves and Xoo 105 exhibited more aggressive reaction on glass house plant and field assay as compared to other isolates. Moreover, all rice tested cultivars showed susceptibility against isolates of BLB disease, Basmati 385 were showed more susceptible reaction.
[Show abstract][Hide abstract]ABSTRACT: In the present study hot water diffusates of different plant species (100gm /100ml) were screened for testing antibacterial activity using hole plate diffusion method against most aggressive isolates of Xanthomonas oryzae Pv.oryzae (Xoo 105). Eight plant species Citrus limon,Linum usitatissimum, Mangifera indica Phyllanthus emblica, Prunus domestica,Tamarindus indica,Terminalia arjuna and Curcuma longa exhibited maximum inhibitory action against test bacterium, among them Curcuma longa member of Zingiberaceae family showed maximum antibacterial activity, forming inhibition zone of 28.45mm in diameter, showing activity index 0.98 compared with streptomycin drug. Extract of Curcuma longa isolated from rhizome were supposed to be Curcumin.
Full-text available · Article · Apr 2011 · Pakistan Journal of Botany
[Show abstract][Hide abstract]ABSTRACT: In this study 33 lines of synthetic hexaploid (SH) of wheat were used for RAPD analysis. These 33 SH were found resistant for stripe rust during the two years of screening at seedling and adult plant stage in field and glasshouse. Total 50 primers were screened and 10 primers of OPA series which were giving the reproducible band were selected for the study of genetic diversity. The result showed the stripe rust resistant synthetic hexaploid of wheat are highly diverse. A total of 108 bands were generated by the ten selected primers, 88 of which were polymorphic. Maximum level of polymorphism (93%) which was observed for the primers OPA-01 while minimum level of polymorphism (36%) was observed by OPA-19 primers. Cluster analysis using the unweighted pair group method of arithmetic averages (UPGMA) clustered the 33 lines into two groups. Eight lines did not form cluster with any of the genetypes and found to be very diverse. These lines can be used by the plant breeders of the country to improve the stripe rust status of the susceptible wheat varieties. Key Words. Stripe rust, synthetic hexaploid RAPDs marker
[Show abstract][Hide abstract]ABSTRACT: Yellow rust populations of Pakistan were characterised for their virulence pathotypes/races and pathogenetic variation using seedling evaluation of differential genotypes under glasshouse conditions in Murree (6000 feet above sea level). Differential genotypes comprised a world set, an European set, near isogenic lines and the universally susceptible bread wheat cultivar “Morocco”. Over the two-year study a total of 18 race groups were identified. Out of these 18 race groups, several (68E0, 64E0, 66E0, 70E0, 6E0, 71E0, 6E0, 2E0, 67E0, and 68E16) were found previously. The new race group 70E32 found probably evolved because of mutation from the previously existing 70E16. Virulence frequencies of yellow rust (Yr) resistance genes were also determined on near isogenic lines. The highest virulence frequencies (%) were found for Yr7 (88%), Yr9 (57%), Yr18 (70%), and Yr24 (69%). Virulence frequencies were low for Yr 1 (4%), Yr5 (7%), Yr10 (10%) and Yr15 (4%). Our studies indicated that virulence existed for almost all yr genes, necessitating regular monitoring of the yellow rust populations and intensifying efforts to identify new sources of resistance to this pathogen.
Full-text available · Article · Jun 2010 · Archives of Phytopathology and Plant Protection
[Show abstract][Hide abstract]ABSTRACT: The crude extracts of 63 plants were used for testing antibacterial activity against Xanthmonas oryazae Pv. oryzae that causes bacterial leaf blight (BLB) in rice plants. Only ten aqueous extracts of botanicals (Thuja orientalis, Prunus domestica, Citrus limon, Allium sativum, Vitis vinefera, Mangifera indica, Phyllanthus emblica, and Terminalia chebula) showed maximum activity against Xanthmonas oryazae in a plate agar diffusion assay. On a detached leaf, in a glasshouse and in a field assay, two potential plant extracts, namely Allium sativum, and Citrus limon showed maximum efficacy in terms of controlling BLB lesions in rice. After isolation through fractionation of the crude extract of Allium sativum, the bioactive compound was purified and characterized as 8-amino(-8-butoxyoct)-2-(enyldisulfanyl)-3-(2hydroxy-4-methoxyphenylprop-1-enyl) benzene-1,3-diol.
Article · Feb 2009 · Archives of Phytopathology and Plant Protection
[Show abstract][Hide abstract]ABSTRACT: Black scurf of potato, Solanum tuberosum L.. caused by the fungus, Rhizoctonia solani is present in all the eight potato producing agro-ecological zones of Pakistan and R.solani anastomosis group (AG) 3 is the major cause of this disease in potato. The present investigations were conducted to study the occurrence of R. solani anastomosis groups (AGs) on this crop. During investigations, 127 R. solani isolates were recovered from potato tuber samples €collected during survey of disease from year 2001 to 2004. All of them were found multinucleate. Anastomosis group determination revealed 81.89% isolates belonging to AG 3 followed by AG 5, 8.66% and AG 4, 5.5%. Occurrence of AG 3 was the highest in all the potato production zones as compared to other AGs indicating R. solani AG 3 isolates pre-dominance on potato. The maximum number of AGs, 5 each, were found in zone 2, the Punjab province (AG1-1A, AG 3, AG 4, AG 5, and AG 9) and zone 7 comprising of parts of Northern areas of the country (AG 2-1, AG 2-2, AG 3, AG 4, and AG 5). It may be concluded from this study that several AGs are associated with black scurf disease. Anastomosis group 3 is the most common group of R. solani on potato here. Therefore, isolates of AG 3 may be used while breeding potatoes for host resistance to R. solani. This is the first report on anastomosis group determination of potato isolates of R. solani or any crop from Pakistan.
[Show abstract][Hide abstract]ABSTRACT: Management of black scurf (Rhizoctoni solani of potato (Solanum tuberosum L.) through determining level of susceptibility in various breeding lines/cultivars of potato and tuber treatment with various fungicides was investigated by Using R. solani AG-3 isolate CL-58 (a known aggressive). Greenhouse screening of fifteen potato breeding lines and cultivars for host plant resistance to isolate CL-58 by soil inoculation revealed potato cvs. Cardinal and Desiree, resistant and susceptible, respectively. Management of disease by using susceptible cv. Desiree through potato tuber treatment with fungicides viz., Dithane M-45, Monceren and Benlate and then sowing them in potting mixture previously inoculated with inoculum of the fungus revealed Dithane M-45, a promising fungicide for of this disease. It significantly checked eyes germination inhibition and decreased sprout killing, stem girdling, stem canker black scruf incidence and severity over non-treated inoculated control. Based upon the results achieved, it is necessary to adopt this practice as seed treatment of chemicals is not a regular exercise in Pakistan. This in-turn will protect potato crop from seed-borne infection and will ultimately lead to better and healthy crop stand.
[Show abstract][Hide abstract]ABSTRACT: During field survey, 525 potato tuber samples weighing 2-5 kg were taken and found that black scurf caused by Rhizoctonia solani was a common fungal disease in all the eight potato production agro-ecological zones of Pakistan. The highest mean disease prevalence, incidence and severity of 99.50%, 65.55% and 2.95 rating, respectively, was found in zone 2, comprising of the Punjab province. The lowest mean disease prevalence 59.19%, incidence 12.81% and severity 1.19 rating was found in zone 7 comprising of Northern Areas of Pakistan. Hundred percent locations surveyed in the remaining six zones were found having this disease. Ten locations in zone 7 namely Booni, Mastuj, Laspur, Shahidaas, Chinar, Garam Chasma, Roi, Norcoraite, Kajal and Murdan were found disease free. These locations could be used for disease free potato seed production. The results of this survey indicate that zone 2, a major potato production area of Pakistan, is heavily affected by black scurf. Moreover, this is the zone which out flows tubers for seed purpose to the remaining potato growing areas of the country. This alarming situation of black scurf at zone 2 demands some emergent multi-dimentional measures instantly be taken with respect to disease management, seed certification, farmers motivation with respect to avoid potato mono-culture and vigilant export of healthy seed tubers to other parts of the country.
[Show abstract][Hide abstract]ABSTRACT: Amongst alien germplasms that provide much needed genetic diversity for resistance to leaf-blotch (caused by Cochliobolus sativus) and karnal bunt (caused by Tilletia indica) is the tertiary gene pool tetraploid Aegilops variabilis (2n=4x=28; UUSS) resource. In order to exploit this species potential, it is crucial that intergeneric hybrids are first produced from which stable genetic stocks are developed for subsequent agricultural utilization. The hybridization of several durum and bread wheat cultivars with Ae. variabilis is reported herein which have yielded cytologically characterized normal F 1 hybrids (2n=4x=28, ABUS or 2n=5x=35, ABDUS). These upon colchicine treatment have generated fertile octoploid and decaploid amphiploids. The amphiploids in all cases possessed aneuploidy that was more pronounced with bread wheat cultivars (2n=10x=70, AABBDDUUSS). Durum amphiploid combinations had more normal 56 chromosome plant types with perfect bivalent meiosis (2n=8x=56, AABBUUSS and 28 bivalents across variable ring and rod associations). Reported here is the cytogenetics of these intergeneric hybrid cross combinations that have enabled the production of a novel genetic resource in the form of fertile amphiploids that hold the potential to address future work on improving wheat cultivars for resistance to C. sativus and T. indica.
Full-text available · Article · Jan 2007 · Pakistan Journal of Botany
[Show abstract][Hide abstract]ABSTRACT: In this study, resistance to stripe rust (Puccinia striiformis) of 95 lines of Elite 1 synthetics, 33 lines of Elite 2 synthetics, and 51 lines of their durum parents were evaluated at the seedling stage in glasshouses at Murree, Pakistan, and at the adult plant stage under field and glasshouse conditions. Bulk inoculum collected during 2004-2005 cropping season was used in all studies. Fifty six entries (58%) of Elite 1 synthetics, 15 entries (45%) of Elite 2 synthetics, and 16 (11%) durum parental entries were found resistant at the seedling stage. In the field and glasshouse the adult plant resistance was evaluated by estimating the area under disease progress curve (AUDPC). Thirty three percent of Elite 1, 30% of Elite 2, and 41% of their durum parents had AUDPC ranging between 0-10 percent. Most of the genotypes resistant at the seedling stage were also resistant at the adult plant stage. Few lines possessed partial resistance as these lines had high infection types at the seedling stage, but low AUDPC at the adult plant stage. Resistance from Aegilops tauschii was identified only at seedling stage in those synthetic hexaploid wheats in which the contributing durum parent was susceptible. The synthetic hexaploid wheats found resistant in this study are potential candidates for bread wheat improvement.
[Show abstract][Hide abstract]ABSTRACT: In the current biochemical investigation the leaves of Saussurea heteromalla were collected from five locations, to study the effect of different altitudes on its chemical composition of this medicinal plant. The biochemical analysis included detection of proteins, carbohydrates and metals. These were studied directly by the atomic absorption spectrophotometric method. A comparative study of proteins and carbohydrates has indicated that proteins and carbohydrate concentrations are not uniform in samples from different altitudal locations except Pir Sohawa. It is further observed that the calcium, magnesium and potassium concentrations were higher as compared to zinc, iron and sodium in samples from varied climates.
Article · Oct 2006 · Journal- Chemical Society of Pakistan
[Show abstract][Hide abstract]ABSTRACT: Fifty one accessions of shisham (Dalbergia sissoo) were assessed to determine the extent of Genetic diversity based on protein variations. These accessions were collected from four different sites for each location i.e. Canal, Road, Farmer's field and Forest site of Punjab province, Pakistan. The assessment of genetic variations at molecular level was carried out by Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) technique. Except three accessions, the 80k.Da (kilo-Dalton) band was found absent in all others. Most of the accessions exhibited 70 k.Da band but was absent in some accessions. Variations with respect to 50k.Da band were observed in accessions of four cities where it was absent. The bands of 60 k.Da, 40 k.Da, 30.k.Da, 20 k.Da, and 10 k.Da were present in all 51 accessions.
Article · Jun 2006 · Journal- Chemical Society of Pakistan