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- Author or Editor: D. R. Bienz x
Training of foreign university students is one of the more important aspects of our nation’s commitment to the betterment of life in developing countries. Because of this commitment, most horticulturists have or will have contact with students from Africa, Asia, South America or the Middle East. Not infrequently, both the student and his American advisors and instructors experience frustrations which result from the different educational experience and social attitude of the foreign student. Spending a year in Turkey has greatly increased my appreciation for the difficulties these people face when they come to the United States for advanced training.
Those responsible for publicly sponsored agricultural research are frequently accused of serving only the interests of large-scale commercial agriculture and the agri-business and agri-chemical industries. Instead of denying this charge, spokesmen for federal and state research institutions often express the opinion that we must concentrate our limited research resources on the primary source of our impressive food and fiber production, which is large-scale agriculture. This kind of rhetoric has nurtured the impression that very little agricultural research is applicable to small farm or garden enterprises, because administrators of agricultural research do not consider these enterprises important. It seemed to us, therefore, that the first requirement in assessing the research and research needs of consumer horticulture was to ascertain the numerical importance of the likely beneficiaries of small farm research and the potential contribution to human welfare of such research. We chose to consider research for all small agricultural enterprises, because the same technology should apply to small, intensively cultivated plots whether they are home gardens, small commercial farms with high value crops, or subsistence farms.
Plant Introduction (PI) accessions of spinach (Spinacia oleracea L.) were evaluated for curly top resistance in greenhouse tests at Pullman and in field tests in the Columbia Basin near Basin City, Washington. In greenhouse tests of 185 accessions, possible resistance was observed in 4 that produced single symptomless plants, in 3 that survived long enough to produce some nonviable seed, and in 56 that produced dwarf green plants in which symptom expression and death were delayed. Of the 178 accessions observed in the field, 13 produced 1 symptomless pistillate plant each, 1 produced a single tolerant pistillate plant, and 1 produced 11 symptomless pistillate plants.
Lines of peas which produce predominantly single, double, and triple pods, respectively, at each peduncle were crossed and growth of the parental lines and the F1, F2 and backcross progenies was compared at 2 temperature regimes—45° night-6O° day and 60° night-75° day—in the growth chamber.
The single-and double-podded parental lines were extremely uniform, producing almost 100% single and double pods, respectively, at both temperature regimes. The triple-podded parent produced almost all 3-podded determinant peduncles at the lower temperature but tended to produce indeterminant peduncles with 2, 3, and 4 pods at the higher temperature.
The F1 of all crosses produced almost all double pods at both temperatures.
The mean numbers of pods per peduncle produced on the F2 plants was somewhat higher at the high than at the low temperature. The F2 and backcross generation plants segregated as they would for a character which is dependent on several genes but for which genes for 2 pods per peduncle showed some dominance. These results contrast with field studies where pod number was extremely variable for all lines and where genes for low pod number appeared to be somewhat dominant.
Field studies of crosses involving lines of peas which produce predominantly 1, 2 and 3 pods at each peduncle showed that inheritance of number of pods is quantitative. As many as 8–9 genes appear to differentiate pod number of the cultivars used in this study.
Estimates of heritability showed that about 50% of the total field variance of pods per peduncle was due to genetic causes. Of this about 17% was due to additive genetic effects.