Most Far Eastern rice varieties are heavily affected by blast, so breeding of resistant samples is of great necessity. The purpose of the current study was to estimate and select androgenic doubled rice haploids Oryza sativa L. with an immune to the rice blast pathogen Pyricularia oryzae CaV. There has been estimated productivity of 36 androgenic lines of doubled rice haploids DH1, identified from seven F1 hybrids under the area vegetation conditions. Thirty-three of them have had resistance alleles of the genes of the Pi family. There has been determined resistance of nine DH1 at an artificial infectious background when inoculating rice plants by spraying with an aqueous suspension of conidia P. oryzae. The study was carried out during two vegetation periods in the FSBSI FSC of Agricultural Biotechnology of the Far East names after A. K. Chaika. There have been identified fifteen lines of doubled rice haploids O. sativa with a pyramid of blast resistance genes, corresponding to the control variety ‘Dolinny’ according to its productivity. Over two years of study, mean grain weight per main panicle ranged from 1.4–2.2 g, grain weight per plant was from 1.5 to 2.0 g, and 1000-grain weight exceeded 27 g. There was a negative effect of the 239 bp allele of the Pi-2 gene individually or in combination with the resistance allele of the Pi-1 gene on the immunity of Far Eastern rice varieties. Individually, the Pi-z and Pi-ta2 genes or a pyramid with their participation provide a stable type of reaction of the DH lines and the variety ‘Dolinny’ to the Primorsky isolates of P. oryza with a mean damage rate from 1.7 to 2.6 points. All lines of doubled haploids were characterized by late-maturity and are of interest in the breeding process as parental forms in hybridization with early maturing varieties O. sativa of the Far Eastern breeding.
The results of research into rice sown for grain (2017–2018) are presented. The effectiveness of Concord fungicide (active ingredients tebuconazole, 125 g/l; triadimefon, 100 g/l) against rice Pyricularia was studied. The experiment was conducted in the conditions of the greenhouse experiment in the Primorsky Territory. Artificial inoculation of plants was carried out in the phase of 4–5 leaves with a suspension of conidia of the fungus Pyricularia oryzae Broomeet Cavara (concentration of 100 thousand in 1 ml). The test results were compared with the action of the preparation Favorit (active ingredients tebuconazole, 125 g/l; triadimefon, 100 g/l). Concord fungicide was used once on the next day after inoculation at a normal rate of 0.75; 1.0 and 1.25 l/ha. Under the influence of the preparation, the damage to rice plants decreased by 57.5% (0.75 l/ ha); 70.0 (1.0) and 69.5% (1.25 l/ ha) compared to the control. The use of fungicide contributed to an increase in plant growth by 7.6– 13.3 cm, and panicle length by 1.4–2.9 cm, and had a positive effect on the number of grains and the weight of grains in an ear. With the action of Concord, the mass of 1000 grains increased by 1.38 (0.75 l/ha); 2.14 (1.0) and 3.03 g (1.25 l/ha) compared to the control. The positive effect of fungicidal treatments of rice crops led to obtaining an additional grain yield. Concord does not show a phytotoxic effect and does not have a retardant effect on rice plants. The maximum indicators of biological efficiency were obtained with the use of the preparation at a flow rate of 1.0 and 1.25 l/ha. In agro-climatic conditions of the south of the Far East, Concord fungicide proved to be effective for protecting rice vegetating plants from Pyricularia.
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