Ai. Mohamed et al., SEED CHARACTERISTICS AND NUTRIENT COMPOSITION OF SELECTED BEANS (PHASEOLUS-VULGARIS L) WITH DIFFERENT OZONE TOLERANCE, Plant foods for human nutrition, 47(1), 1995, pp. 29-38
Ozone sensitivity, nutritional quality, seed characteristics, and grow
th habit of beans (Phaseolus vulgaris L.) were evaluated in two separa
te experiments. In the first experiment the data showed a significant
variation among 34 bean accessions for ozone sensitivity following acu
te exposure of 18-day-old plants to 0.6 mul/l O3 for 2 hours under env
ironmentally controlled greenhouse conditions. PI-163579, PI-169735, P
I-171790, PI-176684, PI-201374, PI-310711, PI-345576, PI-370569, PI-37
9435, and PI-414831 were identified as tolerant to acute ozone exposur
es. Protein, oil, starch, sugar, and ash contents in the seed of selec
ted germplasm were determined and no correlation was found between the
se components and ozone sensitivity. Seed size and growth habit varied
considerably among the 34 accessions but were not correlated to ozone
sensitivity. In a second experiment, ten accessions, selected from th
e tolerant ones identified in the first experiment, were subjected to
chronic ozone exposure in open-top chambers at 0.04 and 0.08 mul/l con
centrations for 7 hours/day 44 days after transplanting. Based on foli
ar injury and yield reductions, only PI-370569 and PI-414831 were tole
rant to prolonged ozone exposure (0.08 mul/l). A significant positive
correlation (r=0.83) existed between foliar injury rating from chronic
treatments involving 0.04 and 0.08 mul O3/l and acute exposure (0.6 m
ul O3/1/2 hours). The data indicated that acute ozone exposure can be
used to initially screen a large number of bean accessions, however, t
his is an imperfect indicator of ozone sensitivity with chronic exposu
re.