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Chickpea (Cicer arietinum L.) plants with foliar and stem lesions fitting the description of Ascochyta blight were observed in October 2002 in four chickpea crops located in the La Araucania Region (38°S, 72°24′W) in southern Chile. Large, circular foliar and stem lesions containing pycnidia arranged in concentric circles were observed (1). Stem breakage also was observed. Isolates were obtained from mature pycnidia developed on stems by culturing a spore suspension on potato dextrose agar (PDA) and chickpea seed meal agar. A pathogenicity test was performed by inoculating 25 plants with a suspension of 1.2 × 105 conidia ml-1 and incubating at 22°C and 75% relative humidity. Foliar and stem lesions were observed 5 and 7 days after inoculation, respectively. Four check plants sprayed with sterile distilled water showed no symptoms. Fungal colonies obtained from inoculated plants showed the same cultural characteristics as the original isolates. Cultural morphology was consistent with the description of Ascochyta rabiei (Pass.) Labrousse (teleomorph Didymella rabiei (Kovacheski) v. Arx (= Mycosphaerella rabiei Kovacheski)) (3). Conidia produced on PDA were predominantly aseptate, 3.90 to 5.85 μm wide, and 9.75 to 11.7 μm long. Affected plants (cv. Kaniva) originated from seed introduced at commercial volumes (69 ton) from Victoria, Australia in August 2002. A. Rabiei can be disseminated via infected seed (1). Ascochyta blight symptoms also have been observed in small patches in several crops near Temuco, the capital of the La Araucania Region. Chickpea production is currently, relatively small in southern Chile, however, plans to promote its cultivation may be hindered by this outbreak. Previously, the only other country to report Ascochyta blight of chickpea in South America was Bolivia (2). References: (1) W. J. Kaiser. Epidemiology of Ascochyta rabiei. Pages 117–134 in: Disease-resistance Breeding in Chickpea. K. B. Singh and M. C. Saxena, eds. ICARDA, Aleppo, Syria, 1992. (2) W. J. Kaiser et al. Plant Dis. 84:102, 2000. (3) E. Punithalingam and P. Holliday. No. 337 in: CMI Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1972.

Fourteen winter-sown genotypes of Lupinus angustifolius L., comprising most of the Western Australian cultivars released since 1986, were studied over 2 years at 4 southern Chile locations. Pod wall proportion, pod wall specific weight, seed number per pod, mean seed weight, seed weight per pod, wall weight per pod, and mean pod weight were measured, separately sampling pods from the mainstem and pods from branches. The 2 pod positions differed significantly for all characteristics except wall weight per pod. Lower coefficients of variation and greater heritabilities for both pod wall proportion and pod wall specific weight were achieved with a sample of pods from branches than with a sample from the mainstem.The ranges for pod wall proportion and pod wall specific weight were small (31.8–35.8% and 27.0–34.7 mg/cm2, respectively); however, highly significant genotypic effects were found for both characters. Heritability estimates were moderate for pod wall proportion (0.27 and 0.44 for pods from mainstem and branches, respectively) and moderate to high for pod wall specific weight (0.56 and 0.61, respectively).Pod wall proportion and pod wall specific weight were significantly correlated, more so at the genetic level (rg�=�0.83 and rg = 0.76 for pods from mainstem and branches, respectively) than at the phenotypic level (rph = 0.57 and rph = 0.60, respectively). Pod wall specific weight was closely associated with wall weight per pod, meaning that larger pods call for thicker pod walls. Accordingly, selection for low pod wall specific weight in a breeding program could lead to light pods. Correlations with mean seed weight indicate that this trait could decrease as well.

Mean seed weight (MSW) is a relevant trait in grass pea (Lathyrus sativus L.) commercialization because large grains are preferred in Western markets. Extending the knowledge on its mode of inheritance among large-seeded types would be useful in breeding programs, and therefore it was the objective of this work. A broad range of MSW is found in grass pea, starting at about 30 mg. Three lines (LS-97, LS-8, and LS-2026) within the large-seeded group but with significantly different MSW (179, 360 and 470 mg, respectively), were crossed in a complete diallel. Part of the F1 seed was sown and the remainder was stored. F1 plants from each cross were allowed to produce F2 seed and some were backcrossed to their respective parents. Parents, F1, F2, and backcross populations were grown in the field in 2006. MSW was obtained from single plants in each population. No difference was observed between reciprocals of crosses LS-97 × LS-8 and LS-8 × LS-2026; therefore, data from reciprocals were combined, assuming nuclear inheritance. However, F2 segregating population from cross LS-97 × LS-2026 and its reciprocal gave significantly different means, suggesting cytoplasmic inheritance. Consequently, F2 and backcross data were handled separately to calculate heritability. Parent lines with high MSW, particularly LS-2026, had greater variances, raising the estimate of environmental variance. Broad sense heritability estimates for MSW were 0.50 and 0.32 for crosses LS-97 × LS-8 and LS-8 × LS-2026, respectively, and 0.23 and 0.24, for cross LS-97 × LS-2026 and its reciprocal, respectively. Narrow sense heritabilities were 0.42 and 0.28, and 0.15 and 0.22, respectively. In all crosses, the genetic effects were predominantly additive, predicting a good response to selection for increased MSW in early segregating generations. Thus, the prospects to improve MSW in large-seeded grass peas are auspicious.

Abstract. The relatively high seed coat proportion of the narrow-leafed lupin reduces its economic value. This character has been shown to be affected by seed weight, and this limits the use of seed coat proportion as a selection criterion. We examined the variation for seed coat specific weight, a potential alternative selection criterion, and tested its relationship with seed coat proportion and seed weight. Seeds were sampled from mainstem pods of 14 winter-sown genotypes of Lupinus angustifolius L. grown at 4 southern Chile sites over 2 years. Seed coat specific weight had an overall mean of 30.1 mg/cm2. Highly significant genotypic effects were found (range 28.9–32.1 mg/cm2). The ranges for sites and years were 29.1–31.1 and 28.9–31.2 mg/cm2, respectively. Genotypes interacted significantly with years, but not with sites. Broad-sense heritability was 0.59, a value that predicts a good response to selection for this character. Seed coat specific weight was weakly correlated (rph = 0.11*) with seed coat proportion, and was not associated with mean seed weight. Seed coat proportion was negatively correlated with mean seed weight (rph = –0.75***) and had high broad-sense heritability (0.95). The correlation between seed coat specific weight and a theoretical seed coat thickness, calculated under the assumptions of equal mass density of seed coat, cotyledons, and embryo, and a spherical-shaped seed, was r = 0.14*. Phenotypic and genotypic correlations between seed coat specific weight and number of seeds per pod were 0.41 and 0.84, respectively. Our results indicate that selection for low seed coat proportion will lead to larger seeded genotypes, but will not reduce seed coat specific weight. Selection for low seed coat proportion after crosses would presumably be effective in reducing seedcoat specific weight if all segregating materials were uniformly large seeded, but that scenario is unrealistic. The evidence presented here suggests that selection for low seed coat specific weight (or measures correlated with it) in segregating populations will be necessary in order to increase the proportion of higher value kernels in seeds and to improve the economic yield of lupins.