The evaluation of parental material of winter rapeseed (Brassica napusL.) and winter brown mustard (Brassica junceaL.) on resistance to Phoma rot in the central zone of the Krasnodar region of the Russian Federation

Abstract

In 2018-2020, Phoma rot (Leptosphaeria maculans Ces. & De Not) in the form of stem canker was the most common disease on winter rapeseed and winter brown mustard in the central zone of the Krasnodar region of the Russian Federation. Given the high prevalence and development of the disease in all years of research, we identified the rapeseed samples resistant to it; they had the affection degree of 1-2 points (9.0-12.0% of the total number of studied samples). The rest of the samples were weakly resistant with the affection degree of 3-4 points (33.0-39.0 % of samples), weakly susceptible with the affection degree of 5-6 points (28.0-40.0 % of samples) and susceptible with the affection degree of 7-9 points (15 0-23.0 % of samples). We also identified the samples resistant to Phoma rot during the examination of mustard. Their number was lower than that of the rapeseed – 3.0-6.0 % of the total number of samples. The main part of the samples was weakly resistant with the affection degree of 3-4 points (47.0-63.0 % of the total number of samples). The rest of the samples during the years of research were weakly susceptible with the affection degree of 5-6 points (11.0-30.0 %) and susceptible (9.0-18.0 %). The parental material of winter rapeseed and winter brown mustard, resistant to disease, can be used as the donors of resistance to Phoma rot in breeding work during the development of the new promising varieties.

Prevalence, Species Structure of Cruciferous Diseases and Their Harmfulness

“…The analysis of the data in Table 1.27 confirms that the resistance of the spring rape variety Kalinovsky is manifested in the ability of affected plant cells to induce an increase in the amount of peroxidase. In addition, our studies also revealed [445] an increase in lignin biosynthesis in the affected tissues of spring rape.…”

“…It has also been proven [445], that in the resistant variety Kalinovsky, the difference in ascorbic acid content in healthy and downy mildew-affected leaves was 2.7 mg%, and in phomosis -3.4 mg%. At the same time, in the relatively susceptible variety Valero, the difference was 12.6 mg% in the first case and 13.9 mg% in the second (Table 1 Similar studies have also shown the role of ascorbic acid in the identification of spring rape downy mildew.…”

“…In addition, it is reported [445] about a 1.16-fold increase in peroxidase activity in leaves of the spring rape variety Kalynivskyi affected by downy mildew compared to the variety Valero. A similar increase in activity (1.17 times) was recorded in phomosis lesions.…”

“…In the process of research [445] the content of nitrogen (protein, nonprotein, total) in rape varieties with different disease resistance was also determined. The table shows that in the affected plants of spring rape of the resistant variety Kalinovsky the content of protein nitrogen is 0.3% higher than in the susceptible variety Valero, non-protein nitrogen -by 0.1%, and total nitrogen, on the contrary, is lower by 0.17% (Table 1 Thus, the studies found that the loss of protein nitrogen in diseased plants of the resistant spring rape variety was less than in a similar disease of a relatively susceptible variety, and the loss of total nitrogen, on the contrary, was greater.…”

Effect of Fusarium blight, Phoma rot, and Sclerotinia blight on rapeseed and mustard plant productivity

“…The stem tissues in this area as well as above and below the necroses become rotted, the stem breaks at this point and the plant becomes lodged. And even if the seeds are formed, they will fall out of the pods or rot inside them [7,8].…”