[Analysis of species and graded features of grain crop resistance to lodging according their physical and mechanical properties and architectonics to use in selection]
2008
Lukjanova, I.V.
The aim of the research is to determine the breeding trends for increasing of resistance to lodging of high-yield varieties and hybrids of grain crops (wheat, barley, rye, triticale, rice, maize, sorghum). The data of architectonics and physical and mechanical properties (stem deformation, stem natural flexure, tissue density) of 70 varieties and hybrids are presented. A stem deflection is determined by a laboratory apparatus constructed by the author. A method to access quantitative characteristics of architectonics and tissue density of grain stems is worked out using a number of indices (average external and internal diameter of a stem assay, assay weight, stem length). This method is recommended to use at estimation of selection grain models for resistance to lodging. The main selection trends for resistance to lodging of studied species is increase of their stem diameters and also decrease of their stem length (except maize, rice and sorghum); increase of stem diameter correlation at a spike and a root (for rye) and increase of elasticity limits for (for rice). Quantitative ranges for the variety parameters are determined: plant height decrease by 11-41%, stem diameter increase by 4-57%, elasticity limit increase in 1.4-1.5 times (for rice only). Optimal parameters of ideal varieties are described, and the analysis of their vertical fastness and stem bending is done. Plant architectonic parameters have to be such as to allow a stem saving vertical fastness while a spike weight is desirable. These data of vertical fastness and stem bending ought to be used in selection practice for resistance to lodging.
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