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Shazia Shafique - One of the best experts on this subject based on the ideXlab platform.

  • cytological and physiological basis for tomato Varietal Resistance against alternaria alternata
    Journal of the Science of Food and Agriculture, 2013
    Co-Authors: Aqeel Ahmad, Shazia Shafique
    Abstract:

    BACKGROUND Since tomato is an important food component, it is imperative to enhance its yield against the activities of many devastating fungal pathogens such as Alternaria alternata. The exploitation of plant innate Resistance by cultivation of resistant varieties is an effective measure in this regard. In the present study, 28 tomato varieties were tested against 32 A. alternata isolates, and representative varieties were further evaluated to determine the extent and basis of their antifungal Resistance. RESULTS A significant increase (104.7%) in polyphenols was recorded in the resistant variety Dinaar compared with the susceptible variety Red Tara. Dinaar also exhibited 100% enhancement of alkaloids and terpenoids along with a 30.7% increase in cell wall hemicellulose content. Significant differences were found in physical barriers (cellulose, lignin and pectin) of the representative varieties when stained tissue sections were subjected to colorimetric analysis. Similarly, polyphenol oxidase, peroxidase and phenylalanine ammonia lyase showed increases of 78.37, 114.67 and 125.11% respectively in the resistant variety. Higher expression of glucanase genes was evident from native gel analysis, in which not only the number of isozymes but also the quantity of individual isozymes was significantly increased. CONCLUSION The resistant variety Dinaar had strong antifungal Resistance and can therefore be recommended as suitable for cultivation in the agricultural system of Pakistan. © 2013 Society of Chemical Industry

R.c. Saxena - One of the best experts on this subject based on the ideXlab platform.

  • Temperature Stress and Varietal Resistance in Rice: Effects on Whitebacked Planthopper
    Crop Science, 1991
    Co-Authors: M. Salim, R.c. Saxena
    Abstract:

    Temperature greatly influences fundamental plant and pest physiological processes and interactions. This phytotron study sought to determine how optimum (29/21 o C), low (24/16 and 26/18 o C), and high (35/27 and 36/28 o C) day/night temperature expression of regimes affect Resistance of IR2035-117-3 (IR2035) and susceptibility of Taichung Native 1 (TN1) rice (Oryza sativa L.) cultivars to the whitebacked planthopper, Sogatella furcifera (Horvath)

  • Nutritional Stresses and Varietal Resistance in Rice: Effects on Whitebacked Planthopper
    Crop Science, 1991
    Co-Authors: M. Salim, R.c. Saxena
    Abstract:

    Nutritional disorders can affect plant growth and a plant's susceptibility to pests. Our objective was to evaluate the effects of N, P, and K stresses on Resistance of ‘IR2035-117-3’ (IR2035) and susceptibility of ‘Taichung Native 1’ (TN1) rice (Oryza sativa L.) plants to whitebacked planthopper, Sogatella furcifera (Horvath), when grown in nutrient solution in a phytotron at 29/21 °C (day/night), minimum 70% relative humidity, and natural daylight of 12 h. Nitrogen, P, or K stresses altered the chemical composition of rice plants. Deficiency of N, P, or K significantly reduced growth of rice plants. Allelochemical production decreased at low K (3 mg/kg) concentration. Insect food intake and assimilation growth, adult longevity, fecundity, and population increased significantly as N increased. In contrast, increases in K application adversely affected the biology and behavior of S. furcifera. Insect response to P-stressed plants was not consistent. Regardless of the levels of N, P, or K, the difference between the Resistance of IR2035 and susceptibility of TN1 remained distinct. Mortality of first-instar nymphs was high on TN1 plants treated with steam-distillate extracts of K-stressed or unstressed IR2035 plants when compared with plants treated with acetone or TN1 extract. Resistance to S. furcifera in rice cultivars thus may be enhanced by applying moderate rates of N and high doses of K. Contribution of the IRRI. Part of a thesis submitted by M. Salim in partial fulfillment of requirements for the Ph.D. degree at the Univ. of the Philippines, Los Banos.

O. C. Umeozor - One of the best experts on this subject based on the ideXlab platform.

  • Efficacy of combining Varietal Resistance with harvest time and planting date for the management of Sitophilus zeamais Motschulsky infestation in stored maize
    Journal of Stored Products Research, 2014
    Co-Authors: Usman Zakka, N. E. S. Lale, O. C. Umeozor
    Abstract:

    Abstract The combination of Varietal Resistance with three harvest times and planting dates for efficient storage of maize against S itophilus zeamais infestation was evaluated in the Niger Delta region of Nigeria for two seasons. Seven maize varieties made up of three susceptible local maize cultivars (Akparike, Bende and Ogbia muno) and four improved resistant varieties (ACR.97 TZL COMP.1-W, TZL COMP.4C2, ADV.NCRE-STR and BG 97 TZE COMP.3XL) were used. There were significant differences in the number of teneral adults among harvest times in all the planting dates in both years. Maize harvested when the cobs were completely dry at the latest harvest time (HVT 3) suffered significantly higher weight losses. In 2009, the highest susceptibility was apparent in a local variety Akparike planted on 17 October (PD 1) and harvested at HVT 3 by which time the cobs had completely turned yellow. Combining early planting and early harvest with resistant varieties could be an appropriate tactic for resource-poor farmers to effectively manage maize weevils in the store in the Niger Delta agro-ecological zone.

M. N. Ukwungwu - One of the best experts on this subject based on the ideXlab platform.

M.o. Ashamo - One of the best experts on this subject based on the ideXlab platform.

  • Varietal Resistance in sorghum to the Angoumois grain moth, Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae)
    Journal of entomological research, 2006
    Co-Authors: M.o. Ashamo, S.c Khanna
    Abstract:

    Studies on Varietal Resistance in sorghum to the Angoumois grain moth, Sitotroga cerealella (Olivier) indicated that IHT 405 was the least susceptible (most resistant) variety (developmental period of 33.3days, adult emergence of 2.3, Susceptibility Index (SI) of 2.7 and weight loss of 1.2%) while AVHT 303 was most susceptible (adult emergence of 15.7, SI of 9.3 and weight loss of 6.1%). Small-sized seeds tend to be less susceptible than larger-sized seeds. Longest, larva to adult developmental period of 34.0 days was observed on IHT 405. The female adult lived longer (9.0 days) than males (8.0 days).

  • Integration of Varietal Resistance and nutmeg, Myristica fragrans (Houtt.) oil in protecting post-harvest infestation by Sitophilus oryzae (L.) in rice
    Journal of entomological research, 2005
    Co-Authors: M.o. Ashamo
    Abstract:

    The highest adult weevil, Sitophilus oryzae (L.) mortality was in rice cultivar FARO 44 (43.3%) and the lowest in ITA 321 (6.7%). FARO 44 was the least susceptible to post harvest infestation caused by S. oryzae with 2.3 adult emergence, lowest percentage weight loss (6.4%) and lowest index of susceptibility (1.8) while ITA 150 was the most susceptible with highest adult weevil emergence (23.3), percentage weight loss (8.8%) and highest index of susceptibility (7.9). Varietal Resistance when integrated with nutmeg oil, the percentage mortality of adult weevils increased with increase in oil concentration. The highest adult weevil mortality of 96.7% occurred within 7 days of application of oil at 4% concentration in rice cultivar FARO 44 indicating feasibility of integration of Varietal Resistance and nutmeg oil in reducing post harvest infestation of S. oryzae in rice.

  • Varietal Resistance of maize to the maize weevil, Sitophilus zeamais Motsch. (Coleoptera: Curculionidae)
    2001
    Co-Authors: M.o. Ashamo
    Abstract:

    Studies on the Varietal Resistance of maize to post-harvest infestation of the maize weevil, Sitophilus zeamais (Motsch.) was carried out in the laboratory at a temperature of 28 ± 2 °C and relative humidity of 75 ± 5 %. The cultivars of maize tested were ACR.91SWAMI/SRCI', 9044-27STR', TZL COMP.4C1', 9021-18STR', 'TZE COMP,4C2', and 'TZESR-WS.E'. They were collected from the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. The infestation of the maize cultivars was done by adding five adult males and 10 adult females to 20 g of each cultivar and replicated three times. The parameters for testing the Resistance were emergence of F1, grain damage and weight loss. An index of susceptibility was also calculated. Resulrs showed that cultivars TZE COMP.4C2', ACR.91SWAM1/SRC1' and TZL COMP.4C1' were the most resistant of all the cultivars tested in term of adult emergence, percentage grain damage and percentage weight loss while 9044-27STR' (the standard), 9021-18STR', and TZESR-WS.E' were the least resistant cultivars. However, cv. TZE COMP.4C2' with index of susceptibility (SI) = 1.12 was the most resistant while TZESR-WS.E' with SI = 4.75 was the least resistant. The initial and final moisture content of the different maize cultivars indicated that none of the cultivars suffered any disadvantage of S. zeamais attack due to the difference in moisture content.