X-RAY EFFECTS ON THE GROWTH AND REPRODUCTION OF WHEAT.
Evidences of miiodification and injury to plant parts are numerous in the extensive literature on the effects of x-ray treatment of plants. JOHNSON (2) lists the effects produced on seventy species of flowering plants. Her work with wheat (3) shows that growing material is more strongly affected than non-growing by equal doses of radiation given in the same way. Seedlings from soaked grains given treatments of 1000 r-units and 5000 r-units made less growth in all respects than did controls, but showed inereased tillering. No flowering data were included. SHULL and MITCHELL (4) obtained deleterious effects when unfiltered radiations were used but the use of metallic screens, high voltage, low amperage, and brief exposures giving approximately 100 r-units, resulted in stimulative action on wheat, corn, oats, and sunflower seedlings. Twentyfour-hour-old wheat seedlings were irradiated with doses of x-rays varying from 565 to 13,560 r-units by FRANCIS (1). Retardation of fresh weight and dry weight production by the growing parts of the seedlings and retardation of linear growth of the coleoptile, the leaf, the primary root, and the lateral roots was obtained with all doses and time intervals employed. Respiration was likewise depressed with the exception of those seedlings which had received the smallest dose of radiation (565 r-units) and which were tested 5 or 6 hours after irradiation. The procedure of SHULL and MITCHELL was closely followed in an attempt to obtain further data on the stimulative effects of filtered x-radiation on growth, height, tillering, heading and flowering, green and dry weights, and moisture content of Marquis spring wheat. An attempt to determine the influence of age of seed on response to irradiation was made by the use of two samples of seed; one 57 months old (4 years, 9 months), the other 9 months old. A preliminary trial was made with Fulhio winter wheat. Methods
THE EFFECTS OF X RAYS AND THERMAL NEUTRONS ON THE DEVELOPMENT OF TRAILING INDIGO (INDIGOFERA ENDECAPHYLLA) PLANTS
DIFFERENT DEVELOPMENT PATTERNS, mostly variations in size, were observed among young plants of trailing indigo (Indigofera endecaphylla Jacq.) arising from seed which had been subjected to various dosages of X rays and thermal neutrons in an attempt to induce beneficial, particularly agronomic, mutations. This study of radiation effects resulted from these observations and the desirability of analyzing the differential growth responses apparently induced by X radiation and thermal neutron flux in dormant seeds of trailing indigo. The existence of a greater quantitative factor, or relative biological efficiency (RBE), for thermal neutrons as compared with X rays is generally recognized. On the basis of equivalent total ionizations, thermal neutrons have about 11 or 12 times the effectivity of X radiation in causing cytogenetic change (Conger and Giles, 1950). In addition to the greater RBE for thermal neutrons as compared with X rays, qualitative differences, different biological effects, have been observed by some workers (Caldecott et al., 1952, 1954; Spencer and Blakeslee, 1955), and denied by others (Snider, 1948; Frolik and Morris, 1950; Schmidt, 1952). Of primary concern in comparative studies of mutagenic agents is whether or not the biological effects of these agents differ in any fundamental way. The initial purpose of this investigation was to study the nature of the different effects noted in trailing indigo plants arising from seed exposed to X radiation and to thermal neutrons. A second purpose was to find if any apparent difference is related to growth substance activity and/or to protein metabolism. MATERIALS AND METHODS.-In order to obtain comparative data concerning the responses of trailing indigo plants to dosages of X rays and thermal neutrons, a series of experiments was designed to analyze effects on germination, survival, development, relative growth substance activity, protein metabolism, and pollen production. Seeds of trailing indigo produced at this station were dried to a moisture content of four per cent (+0.5 per cent), and used throughout these tests. The self-fertility of this legume assured a high degree of homozygosity (manifest by the uniformity of juvenile and adult characters). Separate lots were treated as follows: 0, 5,000, 10,000, 20,000, 40,000, 60,000, 80,000, 100,000, 120,000, 160,000, and 200,000 r;
Comparison between Two Chemicals for Reducing Scale Formation in Reverse Osmosis Systems
In this present research was transacted with the calcium carbonate scale inhibition on the membrane surface of the reverse osmosis desalination system. Influence of changing feed solution flow rate (10-25)l/h, pH of the feed solution (6-10) on the recovery ,penetrate flow rate and total dissolved solid in (RO) system by using solution of calcium carbonate as feed solution was investigated, furthermore the effect of adding two types of scale inhibitor ,zinc chloride and polyamino polyether methylene phosphonate with difference concentration (2-8)mg/l for zinc chloride and (8-15) mg/l for polyamino polyether methylene phosphonate was calculated. The results showed that the permeate rate increases as the feed flow rate augmentation ,while it reducing with time, the total dissolved solids decreases as the feed flow rate increases while it increases with time and recovery rate decreases as the feed flow rate increases and it also decreases with time. It was concluded that the permeate rate decreases as the feed solution pH value increases and it cause high scale forming thus decrease the permeate TDS.By adding the scale inhibitor, it was found that the permeate rate and recovery rates increases as the concentration of inhibitor increases while the total dissolved solids decreases in the permeate with increasing the concentration of both inhibitors .It was discovered that Polyamino polyether methylene phosphonate more sturdy than zinc chloride as scale inhibitor for reverse osmosis desalination system in all concentrations was studied in this article.