Bio-based products control black rot (Xanthomonas campestris pv. campestris) and increase the nutraceutical and antioxidant components in kale.

Black rot of crucifers, (Xanthomonas campestris pv. campestris) is the principal yield-limiting and destructive pathogen of cruciferous crop worldwide. In order to validate a bio-based control alternative for this disease, whey, lime sulfur, biofertilizer, Bordeaux mixture or raw milk were applied to kale (Brassica oleracea var. acephala) plants. The disease control was achieved by most of the tested products. Milk-based products (raw milk and whey) and biofertilizer reduced the severity by 44 and 56% in the field. Antioxidants, crude fibber, crude protein and lipid contents and kale yield were verified in the five treatments on the leaves with and without X. campestris pv. campestris inoculation. In the absence of the pathogen (non-inoculated), lime sulfur and Bordeaux mixture improved plant nutritional value compared to organic treatments, nevertheless milk-based products and biofertilizer improved the evaluated variables more than the control. However, on leaves inoculated with X. campestris pv. campestris raw milk increased antioxidant activity, crude protein and fiber contents, whereas biofertilizer increased kale yield, lipid and antioxidant contents. Milk-based products and biofertilizer were further evaluated in greenhouse trials to determinate the activity of defense-related enzymes and lignin content. Biofertilizer treatment resulted in increased phenylalanine ammonia lyase, catalase, peroxidase activities and lignin content. Hence, the application of milk-based products and biofertilizer are promising to control black rot of crucifers and also improves food quality by boosting nutritional values and antioxidant activity.

Inheritance of parthenocarpy in summer squash (Cucurbita pepo L.).

The inheritance of the tendency to set parthenocarpic fruit in the summer squash (Cucurbita pepo L.) line Whitaker was studied. Two parental lines, Whitaker (parthenocarpic) and Caserta (non-parthenocarpic), and the F1 and F2 generations and backcrosses to both parents were tested. The parthenocarpic tendency of individual plants was scored on a scale from 1 (non-parthenocarpic fruit) to 5 (parthenocarpic fruit). The Whitaker line produced parthenocarpic fruit and had a mean score of 4.2, whereas Caserta did not set parthenocarpic fruit and had a score of 1.55. The heritability estimates indicated that genetic gains from selection were feasible. The additive-dominant model showed a good fit, with epistasis being negligible or nonexistent. The hypothesis of monogenic inheritance with incomplete dominance was not rejected within the degree of dominance range from 0.2 to 0.5. These results indicate that parthenocarpy is controlled by a single locus, with incomplete dominance in the direction of parthenocarpic expression.

Inheritance of resistance to Meloidogyne incognita race 2 in the hot pepper cultivar Carolina Cayenne (Capsicum annuum L.).

Root-knot nematodes of the genus Meloidogyne are important pathogens affecting vegetable crop production in Brazil and worldwide. The pepper species Capsicum annuum includes both hot and sweet peppers; very little emphasis has been placed on breeding sweet peppers for nematode resistance. We report on the inheritance of resistance to Meloidogyne incognita (Kofoid & White) Chitwood race 2 in the hot pepper cultivar Carolina Cayenne. The hot pepper cv. Carolina Cayenne was used as seed parent and the sweet pepper cv. Agronômico-8 was used as pollen parent to obtain the F(1) and F(2) generations and the backcross generations BC(11) and BC(12). The plants were inoculated with M. incognita race 2 at a rate of 60 eggs/ml of substrate and, after a suitable incubation period, the numbers of root galls and egg masses per root system were evaluated on each plant. Broad- (0.77 and 0.72) and narrow-sense (0.77 and 0.63) heritability estimates were high for both root galls and egg masses, respectively. The mean degree of dominance was estimated as 0.29 and 0.25 for numbers of galls and egg masses, respectively; these estimates were not significantly different from 0, indicating a predominantly additive gene action. The results were consistent with a hypothesis of monogenic resistance in Carolina Cayenne.

Inheritance of resistance to Meloidogyne incognita race 2 in the hot pepper cultivar Carolina Cayenne ( Capsicum annuum L. )

Root-knot nematodes of the genus Meloidogyne are important pathogens affecting vegetable crop production in Brazil and worldwide. The pepper species Capsicum annuum includes both hot and sweet peppers; very little emphasis has been placed on breeding sweet peppers for nematode resistance. We report on the inheritance of resistance to Meloidogyne incognita (Kofoid & White) Chitwood race 2 in the hot pepper cultivar Carolina Cayenne. The hot pepper cv. Carolina Cayenne was used as seed parent and the sweet pepper cv. Agronômico-8 was used as pollen parent to obtain the F1 and F2 generations and the backcross generations BC11 and BC12. The plants were inoculated with M. incognita race 2 at a rate of 60 eggs/ml of substrate and, after a suitable incubation period, the numbers of root galls and egg masses per root system were evaluated on each plant. Broad- (0.77 and 0.72) and narrow-sense (0.77 and 0.63) heritability estimates were high for both root galls and egg masses, respectively. The mean degree of dominance was estimated as 0.29 and 0.25 for numbers of galls and egg masses, respectively; these estimates were not significantly different from 0, indicating a predominantly additive gene action. The results were consistent with a hypothesis of monogenic resistance in Carolina Cayenne.