A series of 128 consecutive cases of atrial septal defect in adult patients was analyzed from the standpoint of the course and prognosis. The ages of the patients ranged from 18 to 67 years and the ratio of men to women was 1 to 2. Age distribution when compared with life expectancy tables indicated reduced life expectancy. Clinical analysis revealed that three quarters of the patients were symptomatic, but symptoms were mild to moderate and usually nonprogressive. Hemodynamic analysis revealed significant pulmonary hypertension in 22% of the series, of which 15% had high pulmonary vascular resistance, and significant arterial hypoxemia in 14%. The most serious risk factor in atrial septal defect is severe pulmonary hypertension. This complication, which develops in about 14% of patients with atrial septal defect when they are between 20 and 40 years of age, may be rapidly progressive, leading to shunt reversal, disability, and death. Once established, pulmonary hypertension may progress even when the defect is surgically closed. Heart failure occurs usually in older individuals and is associated mostly with chronic atrial arrhythmias rather than pulmonary hypertension.

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lary rise and evaporation of soil water during the dry season or from salinity of irrigation waters. Salinity tolerance during germination and early seedling growthSalinity impairs seed germination, reduces nodule forwas evaluated for 24 accessions representing four wild Phaseolus mation, retards plant development and reduces crop species (P. angustissimus A. Gray, P. filiformis Bentham, P. leptostayield (Greenway and Munns, 1980). One approach to chyus Bentham, and P. microcarpus Mart.) and four accessions of cultivated common bean (P. vulgaris L.) at 0, 60, 120, and 180 m M reducing the deleterious effects of soil salinity on crop NaCl. Salinity stress delayed germination in all accessions to varying production is the development of salt-tolerant cultivars degrees. Eight accessions of P. filiformis germinated fastest under (Epstein et al., 1980). In certain species, this may be high salinity (120 mM NaCl). Additional wild accessions exhibiting achieved by exploiting intraspecific variability. Howrapid germination at 120 m M NaCl were P. angustissimus, PI535272, ever, when such variability is limited, as occurs in many P. leptostachyus, PI535336, and P. microcarpus, PI430196. Among crop species, genes may be transferred from closely reaccessions, median germination time (days to 50% germination, T50) lated wild species adapted to high salinity (Austin, at 120 mM NaCl was correlated positively (r 2 ϭ 0.55, P Յ 0.01) with 1993). Legumes are considered a relatively salt sensitive germination in the control treatments. Seeds that germinated rapidly family (Maas and Hoffman, 1977) within which limited at 60 m M NaCl also germinated rapidly at 120 m M NaCl. At 180 variability for salinity tolerance has been detected (Garg m M NaCl, several accessions reached 50% germination by 6 d, demonstrating high genetic potential within Phaseolus for salinity toler-and Gupta, 1997; Johansen et al., 1990). In contrast ance during germination. The biomass of radicles plus hypocotyls to the cultivated legumes, the genetic diversity of wild decreased with increasing salinity. Cluster analysis separated the acrelatives may provide useful genes for improving tolercessions into three groups. Group I included salt sensitive accessions ance. For example, there are several wild relatives of with late germination, high sensitivity index (ratio of median germina-

Anacardic acids, a class of secondary compounds derived from fatty acids, are found in a variety of dicotyledonous families. Pest resistance (e.g., spider mites and aphids) in Pelargonium xhortorum (geranium) is associated with high levels (-81%) of unsaturated 22:1w5 and 24:1w5 anacardic acids in the glandular trichome exudate. A single dominant locus controls the production of these w5 anacardic acids, which arise from novel 16:1A11 and 18:1413 fatty acids.We describe the isolation and characterization of a cDNA encoding a unique 49 14:0-acyl carrier protein fatty acid desaturase. Several lines of evidence indicated that expression of this desaturase leads to the production of the w5 anacardic acids involved in pest resistance. First, its expression was found in pest-resistant, but not suspectible, plants and its expression followed the production of w5 anacardic acids in segregating populations. Second, its expression and the occurrence of the novel 16:1A11 and 18:1413 fatty acids and the t5 anacardic acids were specific to tall glandular trichomes.

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