First-intemode bioassay

Since the isolation of BL, BL and its related compounds have been tested by a number of bioassays originally designed for known plant hormones. BRs have been shown to have a broad spectrum of biological activities (3,4,8). Structure-activity relationship of BRs has also been clarified by bean second-intemode bioassay, bean first-intemode bioassay, raphanus test, tomato test, and rice-lamina inclination test (25-57). 

Barley field experiments, description for brassin evaluation, 12 Barley leaf cell ultrastructure, protective effect of brassinosteroids under saline stress, 150,152/153,154/ Bean first-intemode bioassay, 321 Bean second-intemode bioassay activities of compounds, 65,68,69-7Of application, 321 brassin purification, 3-4 brassinosteroids, description, 109-110 development, 321 scheme, 63,65,66/... 

In subsequent years, John W. Mitchell developed two bioassays, popularly known as the bean first intemode and the bean second internode bioassays. The first intemode test was successfully used for screening several commercial chemicals, including such popular pesticidal chemicals as 2,4-D, 2,4,5-T, and Amo 1618. The bean second intemode bioassay did not find immediate application, although gibberellins, including gib-berellic acid (GA showed elongating properties in this test. 

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