Association of Five Characters in Progenies of Four Sugarcane Crosses

Abstract

AH possible phenotypic correlations among fiber percentage, number and diameter of stalks, Brix by hand refractometer, and number of shoots in the spring after first harvest were determined in plant cane seedlings of four sugarcane progenies. Parent clones were complex tri-species hybrids (Sacchamrum officinarum L. ✕ S. sinense Roxb. ✕ S. spontaneum L.). Correlations for fiber with other agronomic characters were made for the first time in large seedling populations. High positive correlations for the four progenies (r = .395**, .516**, .559**, and .651**) were found between fiber and Brix. Simultaneous selection for low fiber and high Brix would be difficult in these progenies. Fiber and diameter of stalks were negatively associated (average r = −.233** for the four progenies). Selection for large diameter of stalks would result in a selected population of lower fiber content unless the genetic correlation (not determined) was near zero or positive. High positive correlations for the four progenies (r = .538**, .561**, .563**, and .716**) between number of stalks and number of shoots in the spring after harvest indicated that number of stalks in plant cane seedlings may be a reasonably reliable index of ratooning ability in seedling populations. All other correlations were quite low. Correlation showed that 6 of the 10 possible character combinations represented undesirable associations. Except for the high positive association of fiber and Brix, none of these associations were high enough to present serious problems in a breeding program. Frequency distributions for characters in each progeny of the four crosses indicated that selection for any one character alone would not be too difficult.