The development of maize (Zea mays L.) varieties as factories of pharmaceutical and industrial compounds has renewed interest in controlling pollen dispersal. The objective of this study was to compare gene flow into maize fields of different local pollen densities under the same environmental conditions. Two fields of approximately 36 ha were planted with a nontransgenic, white hybrid, in Ankeny, Iowa, USA. In the center of both fields, a 1-ha plot of a yellow-seeded stacked RR/Bt transgenic hybrid was planted as a pollen source. Before flowering, the white receiver maize of one field was detasseled in a 4:1 ratio to reduce the local pollen density (RPD). The percentage of outcross in the field with RPD was 42.2%, 6.3%, and 1.3% at 1, 10, and 35 m from the central plot, respectively. The percentage of outcross in the white maize with normal pollen density (NPD) was 30.1%, 2.7%, and 0.4%, respectively, at these distances. At distances greater than 100 m, the outcross frequency decreased below 0.1 and 0.03% in the field with RPD and NPD, respectively. A statistical model was used to compare pollen dispersal based on observed outcross percentages. The likelihood ratio test confirmed that the models of outcrossing in the two fields were significantly different (P is practically 0). Results indicated that when local pollen is low, the incoming pollen has a competitive advantage and the level of outcross is significantly greater than when the local pollen is abundant.
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http://dx.doi.org/10.1007/s00484-007-0088-5 | DOI Listing |
PLoS One
December 2024
Department of Earth and Environmental Sciences, State University of New York at Potsdam, Potsdam, New York, United States of America.
Two radiocarbon-dated pollen and charcoal records from cores collected at Stump Pond and a wetland in suburban Albany County, New York, provide new insights into the environmental history of a unique inland pine barrens that is currently surrounded and threatened by urban development: the Albany Pine Bush (APB). The Stump Pond core shows that the pond formed roughly 13,000 years ago with the recession of glacial Lake Albany. From ca.
View Article and Find Full Text PDFJ Adv Res
December 2024
Department of Urology, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China; Hubei Hongshan Laboratory, Wuhan 430071, China. Electronic address:
Plant Cell
December 2024
State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Joint Center for Life Sciences, Beijing Advanced Center of RNA Biology (BEACON), School of Life Sciences, Peking University, Beijing 100871, China.
Starch is an indispensable energy reserve for pollen and failure of starch biosynthesis in pollen leads to male sterility in flowering crops. Nonetheless, the regulatory mechanisms underlying starch biosynthesis in rice (Oryza sativa) pollen remain unclear. Here, we identified a target of the microRNA OsmiR159, SPOROCYTELESS ETHYLENE-RESPONSIVE ELEMENT BINDING FACTOR-ASSOCIATED AMPHIPHILIC-REPRESSION 2 (OsSPEAR2).
View Article and Find Full Text PDFJ Health Econ
November 2024
Syracuse University and NBER, Syracuse, NY 13202, USA. Electronic address:
Traffic fatalities are the leading cause of mortality in the United States despite being preventable. While several policies have been introduced to improve traffic safety and their effects have been well documented, the role of transitory health shocks or situational factors at explaining variations in fatal traffic accidents has been understudied. Exploring daily variation in city-specific pollen counts, this study finds novel evidence that traffic fatalities increase on days in which the local pollen count is particularly high.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, China. Electronic address:
Photo-thermo-sensitive genic male sterility (PTGMS), which exhibits varying fertility levels under different environmental conditions, is a crucial method for heterosis utilization in wheat. However, the mechanisms underlying fertility conversion remain unclear. In the study, three BS type PTGMS lines were analyzed to study fertility conversion characteristics.
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