The effects of cadmium in a concentration similar to that found in Maharloo Lake (Shiraz, Iran) on male reproductive system was studied in adult Balb/c male mice that received 0, 23, and 50 mg/kg of cadmium chloride in 0.5 mL distilled water for 45 days. Sperm count and motility, sperm nuclear maturity and chromatin structure tests were carried out. Testis of each mouse was examined histologically. The treated male mice were mated with females. Prostatic and nonprostatic acid phosphatase activity in blood serum, testis, and prostate, lipid peroxidation and cadmium accumulation in testis, seminal vesicle, and middle 1/3 of the quadericeps femoris muscle were measured. The sperm count, sperm motility, sperm maturity, and the level of testosterone decreased significantly in the high dose adminstered group. Histological studies showed a severe necrosis and atrophy in the testis of high dose group, consequently, there was no successful mating in some groups. The number of newborns and their weights and crown rump lengths reduced. Cadmium accumulation in testis and middle of the quadriceps femoris muscle was significantly higher in animals receiving 50 mg/kg cadmium chloride. Nonprostatic acid phosphatase activity decreased, whereas prostatic acid phosphatase activity increased significantly in serum of animals receiving 50 mg/kg cadmium chloride. Also prostatic acid phosphatase activity decreased significantly in prostate of animals receiving 50 mg/kg cadmium chloride. Lipid peroxidation was significantly higher in testis of animals treated with 50 mg/kg cadmium chloride compared with control group. Cadmium affects male reproductive system activity and can cause infertility in mice as an animal model.

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Soybean (Glycine max (L.) Merr.) pollen movement was studied by evaluating the frequency of outcrossing on white‐flowered (recessive) male‐sterile plants sampled at various within and between‐row distances from a purple‐flowered (dominant) pollen source. In 1973, five 2.75‐m within‐row segments from 0.0 to 13.75‐m and three between‐row distances from 2‐m to 9‐m were evaluated. The data indicated a linear reduction (from 8.3 to 1.4%) in the amount of purple‐flowered progeny as both within and between‐row distances increased.In 1974, six 6.1‐m within‐row segments from 0.0 to 36.6‐m and 12 between‐row distances from 1.0 to 23.0‐m from the purple‐flowered pollen source were evaluated. The 1974 results indicated that with between‐row distances of at least 7‐m and within‐row distances of at least 12 to 18‐m from the pollen source, little pollen contamination would occur. The percentage of purple‐flowered progeny found at these distances or beyond averaged 0.4%. These results indicated that most outcrossing occurred with surrounding plants, and thus intermating blocks of soybeans could be located adjacent to other soybean experiments or commercial plantings without high levels of pollen contamination.

The effects of temperature, 02, and CO2 on titratable acid content and on CO2 exchange were measured in detached pineapple (Ananas comosus) leaves during the daily 15-hour light period. Comparative measurements were made in air and in C02-free air. Increasing the leaf temperature from 20 to 35 C decreased the total CO2 uptake in air and slightly increased the total CO2 released into C02-free air. Between 25 and 35 C, the activation energy for daily acid loss was near 12 kcal mol-', but at lower temperatures the activation energy was much greater.Increasing 02 or decreasing the CO2 concentration decreased the total CO2 fxation in air, whereas the total CO2 released in C02-free air was increased. The total acid content remained constant at 20 C, but it decreased progressively with increasing temperature both in air and in C02-free air. The total acid content at 30 C remained constant in 2% 02 irrespective of CO2 concentration. The total acid content decreased in 21 and 50% 02 as the CO2 increased from 0 to 300, and 540 ,ul/I of CO2. The data indicate that photorespiration is present in pineapple. The revealed that the RQ is low or zero during dark acidification in C02-free air. In air, however, a negative RQ is observed since CO2 is taken up by the leaves. After maximum dark acidification is reached, the RQ increases and often rises well above 1.00 (15). The effect of 02 on photosynthetic CO2 uptake has been studied by several investigators (4,9, 11). It is well established that 02 concentrations above roughly 2% inhibit CO2 fixation in C3 plants, whereas C4 photosynthesis is relatively insensitive to changes in 02 concentration (4, 9, 11). This inhibitory effect of 02 on C3 photosynthesis is postulated to be due to photorespiration.The presence of photorespiration in CAM plants was suggested by Crews et al. (5) when they observed a biphasic postillumination CO2 burst (PIB) in pineapple and other CAM plant leaves. Decreasing 02 or increasing CO2 eliminated the primary PIB peak without affecting the secondary peak. An increase in light-dependent CO2 fixation with increasing CO2 concentration also was reported both in Kalanchoe daigremontiana (1) and in pineapple leaves (5). Osmond and Bjorkman (14) showed in K. daigremontiana that 02 at concentrations from 4 to 36% substantially inhibited CO2 fixation in the light. But with CAM plants, changing the gas phase around a leaf will give a variety of responses throughout a day (5); so that data are complex to interpret or explain since the strong diurnal CAM cycles are involved.On the basis of these observations, a series of experiments in controlled environments was initiated to study photorespiration, photosynthesis, and other aspects of carbon metabolism in de-