Studies on the reproductive biology of downy brome (Bromus tectorum)

Thesis/Dissertation · Wed Jan 01 00:00:00 EST 1986

OSTI ID:5117764

Richardson, J M

The ability of downy brome to successfully infest crop lands is partially due to its prolific nature. To better understand its reproductive biology, studies investigating (1) effects of temperature and photoperiod on flowering, (2) prevention of downy brome seed information with herbicides, and (3) effects of drought on reproduction, were conducted. Seedling vernalization was more effective than seed vernalization in promoting downy brome flowering. Vernalizing imbibed downy brome caryopses at 3 C for 0 to 30 days did not induce rapid flowering. Downy brome seedlings were exposed to six photoperiod/temperature treatments. After transfer to long days, plants from the short da/3 C treatment flowered within 30 days. DPX-Y6202 and fluazifop-butyl were tested for their ability to prevent seed formation in downy brome. Fluazifop-butyl prevented seed formation over a wider range of application rates and growth stages than did DPX-Y6202. Seed production was prevented most readily by herbicide applications made early in the reproductive cycle. Translocation of radiolabel was greater with /sup 14/C-fluazifop-butyl than with /sup 14/C-DPX-Y6202, particularly into developing spikelets. Microautoradiographic techniques were used to identify mechanisms involved in the prevention of downy brome seed formation by these herbicides. Tissue localization of both herbicides was similar. The highest concentration of radiolabel was found in developing pollen grains, suggesting that the herbicides prevented seed formation by interrupting pollen development or function. Water stress reduced apparent photosynthesis and increased diffusive resistance of flag leaves.

• Research Organization: Washington State Univ., Pullman (USA)
• OSTI ID: 5117764
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
GRASS
REPRODUCTION
TEMPERATURE EFFECTS
HERBICIDES
BIOLOGICAL EFFECTS
AUTORADIOGRAPHY
BIOLOGICAL STRESS
CARBON 14 COMPOUNDS
FLOWERS
MOISTURE
PLANT GROWTH
POLLEN
SEEDS
VISIBLE RADIATION
ELECTROMAGNETIC RADIATION
GAMETES
GERM CELLS
GROWTH
LABELLED COMPOUNDS
PESTICIDES
PLANTS
RADIATIONS
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560303 - Chemicals Metabolism & Toxicology- Plants- (-1987)
551001 - Physiological Systems- Tracer Techniques