Lodging resistance of modern domestic rice varieties

Lodging is a complex process that expresses the plant’s response to environmental factors. The main direction of breeding grain crops is to increase yields and improve the grain quality indicators. For the plants to form the maximum yield, it is necessary to develop varieties with a high potential for productivity and quality, resistance to biotic and abiotic environmental factors. In this regard, 5 new rice varieties of domestic breeding were studied in comparison with the large-grain standard Favorit on an optimal background of mineral nutrition and they were evaluated for a complex of traits and for lodging resistance. The experiment was carried out in 2019-2020 under the conditions of field experment on the rice irrigation system of the experimental production department (ROS OPO) “FSC of Rice” (Federal Scientific Rice Centre), Krasnodar. A significant difference was established between the new rice varieties in comparison with the standard in terms of the complex of anatomical and morphological traits - the maximum values of the diameter of the lower internode (0.80 and 0.78 cm) were observed in VNIIR 10275 and VNIIR 10254, respectively; the predominant ratio of the height of the straw to the diameter of the lower internode (90.8 and 120.7) was established at VNIIR 10254 and Veles; the new genotypes showed a reliably high resistance of the stem to bending with the maximum value for VNIIR 10275 (165.75 g). The important structural elements of productivity of new varieties were determined and the excess of some of them over the variety Favorit was revealed: high density of the main panicle in the varieties Romans and VNIIR 10279 (12.2 and 11.8 pcs / cm); VNIIR 10254 has a large caryopsis and the largest weight of 1000 grains at 14% moisture content (43.1 g); at VNIIR 10275 and VNIIR 10279, the maximum productivity of one growing day (100.4 and 110.4 kg / ha / day) and grain content of agrophytocenosis (50.00 and 58.19 thousand pieces / m 2 ) were established. A close positive relationship was revealed between the stem’s resistance to bending and the diameter of the lower internode (r = 0.930), as well as a negative correlation of the average degree between the grain mass of the main panicle with the stem’s bending resistance (r = -0.552) and the diameter of the lower internode (r = -0.530). Based on the data obtained, it was decided to transfer the variety VNIIR 10279 (Dialog) for 2021 to the State Variety Testing (SVT).