Abstract:In order to understand the genetic characteristics and effects of combination selection of Yuetang parents of sugarcane (Saccharum officinarum), the genetic effects, economic breeding values of 6 main traits of F1 population from 55 combinations were estimated by using family test method, which families were combined from 6 Yuetang parents, such as ‘YT00-236’, ‘YT03-373’, ‘YT93-159’, ‘YT94-128’, ‘YT99-66’, and ‘YT08-1966’. The results showed that among six parameters, the stalk diameter was controlled primarily by female and male additive genes effects and non-additive genes effects. The plant height, brix, sugar content and cane yield were mainly controlled by male additive genes effects and non-additive genes effects. The tiller number was controlled just by male additive genes effects. The general combining ability (GCA) of cane yield and economy breeding value (EBV) in ‘YT94-128’ as female were the highest among six varieties, which could be used as high-yield female, while ‘YT93-159’ possessed the highest GCA of sugar content and relatively high EBV as male, which could be used as high-sugar male. Among the 55 combinations, the cross combinations ‘YT94-128’בGuitang02-761’, ‘YT00-236’בGuitang94-119’ and ‘Guitang02-467’בYT93-159’ had better special combining ability and EBV than the others, which could be considered as the most important productive families. Therefore, these would provide helpful information for using Yuetang parents in cross combination.

Abstract:In order to understand the heterosis of yield-related and quality characters in two-line hybrid progenies of Setaria italica, 18 hybrid combinations were designed with three male sterile lines (A1, A2, A3) and six herbicide resistant restorer lines (R1, R2, R3, R4, R5 and R6) by using incomplete diallel cross (NCⅡ), the eleven phenotypic characteristics of combining ability and the hereditability were analyzed, such as plant height, grain weight, protein content, and so on. The results showed that there were significant differences in quantitative traits among two parents and their combinations. Among all the traits, the plot yield of hybrid combination was significantly correlated with thousand-seed weight (TSW), ear weight (EW), plant height (PH), and ear length (EL), but not significantly related with quality traits, such as crude protein, crude fat and total starch. The general combining ability (GCA) effect values of different characters varied significantly in different parents. Meanwhile, A1 (male sterile line) and R1 (restorer line) had high positive effect values of GCA among most of yield and quality traits, which was potential parents for improving the high yield and quality of foxtail millet. However, it was noteworthy that the presentation of specific special combining ability (SCA) in combinations was not completely consistent with effect values of GCA in their parents. Among eighteen combinations, A1×R5, A1×R6, A2×R1, A2×R4 displayed high SCA effect, and showing excellent combinations. Furthermore, the broad-sense heritability and narrow-sense heritability of all quantitative traits were more than 65%, mainly co-controlled by additive effects and non-additive effects. PH, EW, and yield of S. italica hybrids had significant mid parent heterosis, and some combinations had strong super parent heterosis. In addition, the narrow-sense heritability value of PH, EL TSW, ear code, and crude fat content were higher than that of other traits, while the non-additive genetic effects of EW, stem node number and protein content were more prominent. Although the heterosis characteristics of yield and quality traits were different, they were determined by additive and dominance effect in the total genetic variation.

Abstract:The combining ability and heritability were estimated in progenies of 12 cross combinations of sugarcane （Saccharum officinarum L.） hybridized by using a incomplete diallel cross design for four female and three male parents. Six parameters were used for the analyses of quality characters in sugarcane juice, i.e. brix （percentage of total soluble solids）, polarilneter reading （PR）, pol in juice （Pol）, sucrose content （SC）, apparent purity （AP）, and gravity purity （GP）. The results showed that the heredity of quality characters was induced mainly by additive gene effects. The changes in brix, PR, Pol and SC were affected by male parents. Parents with high sugar-yielding and good combining ability appeared in CP72-330, HoCP93-750, GT91-116 and YT92-1287 which presented high and positive general combining ability （gca）. Whereas for progenies of crosses, CP72-330×GT91-1 10 and HoCP93-750×YT92-1287 showed high and positive special combining ability （sea）. The gca variances in male parcnts were greater than those in female ones. The gca variances in parcnts were grcater and sea variances in crosses by 7 to 28 times. The heritability in broad sense （hB2） in quality characters were from 58% to 68%, and that in narrow sense （hN2） 56%-60%. These results indicated that the data of quality characters had better heritability.