The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform

Bent Skovmand - One of the best experts on this subject based on the ideXlab platform.

  • the influence of Glume pubescence on spikelet temperature of wheat under freezing conditions
    Functional Plant Biology, 2001
    Co-Authors: Benoit Maes, Matthew P Reynolds, Maarten Van Ginkel, Richard Trethowan, Bent Skovmand
    Abstract:

    Synthetic hexaploid wheat lines possessing pubescent Glumes were observed to suffer less frost damage during flowering than non-pubescent plants, after experiencing a damaging frost in the field during April 1997. In order to test the potential advantage conferred by Glume pubescence, pubescent and non-pubescent plants were selected from a collection of synthetic hexaploid wheat lines, as well as from F 4 -derived F 7 lines selected from crosses between pubescent synthetic parents and non-pubescent elite spring bread wheat lines. Comparisons of floret temperature between pubescent and non-pubescent plants were carried out in a controlled temperature chamber. Freezing was determined by the appearance of an exotherm, the point in time at which water changed from liquid to solid phase. Flowering plants grown in pots were subjected to a 6-h period of temperature change ranging from 20 to –4˚C. Floret temperature was measured using micro-thermocouples attached to a data logger. Results indicated that the temperature of pubescent florets was higher than that of their non-pubescent equivalents. Significant temperature differences between the florets of pubescent and non-pubescent plants varied between 0.25 and 0.47˚C when the floret temperature of non-pubescent plants reached 0˚C. The appearance of the exotherm was delayed by as much as 3.27 min when pubescence was present. Pubescent plants also produced a higher number of grains per spikelet compared to non-pubescent plants. These observations suggest that Glume pubescence is a factor that will influence the damaging effects of frost at or following anthesis.

  • Glume Pubescence and Its Influence on Spikelet Temperature of Wheat under Freezing Conditions
    Wheat in a Global Environment, 2001
    Co-Authors: Benoit Maes, Matthew P Reynolds, Richard Trethowan, M. Van Ginkel, Bent Skovmand
    Abstract:

    Newly produced synthetic hexaploid wheats possessing pubescent Glumes were observed to suffer less frost damage than non-pubescent plants after experiencing severe frosting in the field during April 1997. In order to test the potential advantage conferred by Glume pubescence, pubescent and non-pubescent plants were selected from a collection of synthetic hexaploid wheats, as well as from F4 derived F7 lines selected from crosses between pubescent synthetic parents and elite spring bread wheat lines.

Benenati N F - One of the best experts on this subject based on the ideXlab platform.

  • Sources and Mechanisms of Resistance to Sorghum Head Bug, Eurystylus-Immaculatus Odh in West-Africa
    International Centre of Insect Physiology and Ecology Nairobi Kenya, 1994
    Co-Authors: Sharma H C, Doumbia Y O, Haidara M, Scheuring J F, Ramaiah K, Benenati N F
    Abstract:

    Sorghum is one of the most important cereal crops in West Africa, and the head bug, Eurystylus immaculatus Odh. (Hemiptera: Miridae) is the key pest of grain sorghum in this region. A range of sorghum genotypes were evaluated for resistance to sorghum head bug at Sotuba (Mali) and Kamboinse (Burkina Faso). Genotypes CSM 388, IS 14332, Malisor 84-7, Sakoika. S 29 and Kamboinse local were resistant to head bugs. both under natural and headcage screening. Head bug resistant genotypes had a lower percentage of head bug damaged grain. The food quality of head bug damaged grain was very poor and unacceptable. Cultivar non-preference was identified as a component of resistance to head bugs. and CSM 388 was nonpreferred compared to E 35-1. Panicle compactness was positively associated with head bug numbers and grain damage. However, genotypes with loose panicles were also susceptible to bugs. Long Glumes (>5 mm), days to Glume opening (>20 days after anthesis), >50% covering of the grain by the Glumes, and grain hardness contribute towards resistance to Eurystylus immaculatus. This information will be useful for developing a programme to breed for resistance to this insect in West Africa

Michael J. Wingfield - One of the best experts on this subject based on the ideXlab platform.

  • Fusarium Glume spot of wheat : a newly recorded mite-associated disease in South Africa
    Plant Disease, 1996
    Co-Authors: G. H. J. Kemp, Z. A. Pretorius, Michael J. Wingfield
    Abstract:

    Fusarium poae was frequently isolated from necrotic lesions on wheat Glumes in South Africa. Glume infections were usually associated with the mycophageous mite Siteroptes avenae. Microscopic examination of S. avenae feeding on F. poae cultures revealed the presence of two elongated sporothecae containing microconidia of the fungus. Spray inoculation of adult wheat plants with a suspension of F. poae microconidia produced water-soaked lesions on leaves and black chaff-like symptoms and necrotic awns. When the suspension was injected through the Glumes into florets, or when F. poae-fed mites were transferred to the Glumes of uninfected plants, symptoms typical of those observed in the field were reproduced. A close association appears to exist between S. avenae and F. poae and evidence suggests that both the mite and fungus are responsible for causing Fusarium Glume spot of wheat in South Africa.

X G Zhou - One of the best experts on this subject based on the ideXlab platform.

  • first report of bacterial panicle blight of rice caused by burkholderia glumae in south africa
    Plant Disease, 2014
    Co-Authors: X G Zhou
    Abstract:

    In April 2013, upright, straw-colored panicles were observed in rice (Oryza sativa L.) fields with center pivot sprinkler irrigation at Ukulima farm in Limpopo Province, South Africa. Affected panicles contained florets that initially exhibited discoloration ranging from light green to light brown on the basal portion of the Glumes and later developed a reddish-brown margin separating this area from the rest of the Glume that became straw-colored. The stems of infected florets remained green. Affected grains were partially filled or aborted, causing panicles to remain upright. These symptoms appeared on approximately 25% of the rice plants of the varieties Presidio and WAB56-104. A gram-negative, rod-shaped bacterium was isolated consistently from symptomatic panicles. These strains produced circular, smooth-margined, convex colonies on King's B medium (KB) with a yellowish-green, diffusible non-fluorescent pigment. Four strains, two from each of the two varieties, were selected for physiological, molecul...

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

  • a putative lipase gene extra Glume1 regulates both empty Glume fate and spikelet development in rice
    Plant Journal, 2009
    Co-Authors: Haoge Li, Wenying Xu, Zhuo Xing, Danian Huang, Qian Qian
    Abstract:

    Recent studies have shown that molecular control of inner floral organ identity appears to be largely conserved between monocots and dicots, but little is known regarding the molecular mechanism underlying development of the monocot outer floral organ, a unique floral structure in grasses. In this study, we report the cloning of the rice EXTRA Glume1 (EG1) gene, a putative lipase gene that specifies empty-Glume fate and floral meristem determinacy. In addition to affecting the identity and number of empty Glumes, mutations in EG1 caused ectopic floral organs to be formed at each organ whorl or in extra ectopic whorls. Iterative Glume-like structures or new floral organ primordia were formed in the presumptive region of the carpel, resulting in an indeterminate floral meristem. EG1 is expressed strongly in inflorescence primordia and weakly in developing floral primordia. We also found that the floral meristem and organ identity gene OsLHS1 showed altered expression with respect to both pattern and levels in the eg1 mutant, and is probably responsible for the pleiotropic floral defects in eg1. As a putative class III lipase that functionally differs from any known plant lipase, EG1 reveals a novel pathway that regulates rice empty-Glume fate and spikelet development.

  • A putative lipase gene EXTRA Glume1 regulates both empty-Glume fate and spikelet development in rice
    The Plant journal : for cell and molecular biology, 2008
    Co-Authors: Dawei Xue, Zhuo Xing, Danian Huang, Qian Qian, Zhenyu Gao, Meixian Yan, Yongbiao Xue
    Abstract:

    Recent studies have shown that molecular control of inner floral organ identity appears to be largely conserved between monocots and dicots, but little is known regarding the molecular mechanism underlying development of the monocot outer floral organ, a unique floral structure in grasses. In this study, we report the cloning of the rice EXTRA Glume1 (EG1) gene, a putative lipase gene that specifies empty-Glume fate and floral meristem determinacy. In addition to affecting the identity and number of empty Glumes, mutations in EG1 caused ectopic floral organs to be formed at each organ whorl or in extra ectopic whorls. Iterative Glume-like structures or new floral organ primordia were formed in the presumptive region of the carpel, resulting in an indeterminate floral meristem. EG1 is expressed strongly in inflorescence primordia and weakly in developing floral primordia. We also found that the floral meristem and organ identity gene OsLHS1 showed altered expression with respect to both pattern and levels in the eg1 mutant, and is probably responsible for the pleiotropic floral defects in eg1. As a putative class III lipase that functionally differs from any known plant lipase, EG1 reveals a novel pathway that regulates rice empty-Glume fate and spikelet development.