No abstract

Roots of Glycine max (L.) Merr. varieties absorb chloride ions in comparable amounts, but subsequent translocations of chlorides to plant tops is genetically controlled. Some varieties accumulate relatively large amounts of chlorides in plant tops; others exclude them almost completely. Chlorides occur in petioles and leaflets, with higher concentrations in leaflets, but whole leaf samples can be used to classify chloride‐accumulating capacity.The chloride includers growings in the saline soils of the Imperial Valley of California develop severe leaf necrosis from chloride toxicity, whereas the chloride excluders show no necrosisCrosses between parents with similar chloride accumulating capacity gave F2 and F3 progeny similar to parents in chloride content. In eight crosses from parents dissimilar in chloride accumulation, F2 plants segregated in ratios of 3 chloride excluder to 1 includer. In tests of the F3 progeny from these crosses, the F2 excluder plants segregated in ratios of 1 excluder to 2 segregating, whereas the F2 includer plants bred true.In backcrosses of the F1 plants from an includer by excluder cross, the segregating ratio was 1 includer to 1 segregating line when the recurrent parent was an includer and 1 excluder to 1 segregating line when the recurrent parent was an excluder.The gene symbols Nel and nel are proposed as the dominant for chloride excluders and the recessive for chloride includers, respectively.

Synopsis In soils free of soybean rhizobia, some strains of Rhizobium japonicum were more effective than others on Lee soybeans. In rhizobia‐contaminated soil, none of the strains caused any detectable growth responses on seed‐inoculated plants.

Synopsis With successive delays in planting, the time from planting to flowering was reduced more for later varieties than for earlier varieties. In contrast, the time from flowering to maturity was reduced more for earlier than for later varieties. Maturity was delayed relatively little by each successive delay in planting. Date of planting affected the seed yield of intermediate and late varieties considerably more than that of the very early and very late varieties.

An understanding of the interrelationships of growth characters is needed to improve breeding of safflower, Carthamus tinctorius L. The objectives of the study were to evaluate five plant characters and four seed characters as units of selection and to determine the optimum combination of years, locations, and dates of planting for testing cultivar performance. Indirect yield components (plant height∕plot, canopy depth∕plant, canopy width∕plant, and head diam∕plant) were intercorrelated. They were also correlated to seed yield and to seeds∕head but with the exception of head diam∕plant they were not correlated to seed weight. The direct yield components (heads∕area, seeds∕head, and seed weight) were not intercorrelated but they were all correlated to seed yield. In several tests involving seven cultivars, variance components were usually significant for plant height, heads∕section, and seed weight and usually nonsignificant for canopy depth, head diameter, and seeds∕head. Cultivar × date of planting and cultivar × location interactions were generally nonsignificant. However heads∕section, seeds∕head, and seed weight showed significant interactions of cultivars with location and date of planting and made it evident that a single year's testing did not adequately evaluate these effects. Cultivar × year interactions were not significant when the data from only one location, Mesa, were analyzed. However when all three locations were considered, some significant interactions appeared. Expected variances of varietal means for heads∕section, seed yield∕section, and seed yield∕plot were calculated for all combinations of environments and also extrapolated to six replications. Expected variances were virtually identical for the second and third years and second and third planting dates. Satisfactory precision for these characters was obtained for the cultivars tested using the combination of 2 years, two locations, two dates of planting, and four replications.