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Melilotus albus Medik. is a legume species with potential to be used as a forage or conserved fodder in Northwest China. Breeding M. albus as a forage crop is focused on simultaneously improving forage yield and reducing coumarin (Cou) content. The goal of the present study was to estimate genotypic variation for several key agronomic traits and to evaluate the impact of single-trait selection and Smith--Hazel-index-based multitrait selection for herbage dry weight (DW), plant height (PH), stem number (SN), and leaf area (LA). A quantitative genetic analysis was conducted on trait measurements from 25 half-sib (HS) families evaluated at Yuzhong and Linze, in China. Significant (P < 0.05) genotypic variation among the HS families for all traits was observed. There was also significant (P < 0.05) genotype x environment interaction for all traits except for LA. The predicted genetic gain, based on estimated genotypic variance, for single-trait selection varied from 2.3 to 30.3% per selection cycle. Pattern analysis of the HS family ´ multitrait best linear unbiased prediction matrix provided a graphical summary of the association among the traits, as well as the four HS family groups generated from clustering. Some members within Group 1 could be crossed to generate a breeding population to be used in recurrent selection for M. albus cultivar development in Northwest China. The applicability of a Smith--Hazel selection index to increase expression of the traits DW, PH, and SN and reduce LA, indirectly reducing Cou content, was confirmed. This index enabled identification of families for increasing key biomass traits and decreasing Cou production. [ABSTRACT FROM AUTHOR]

The article focuses on the registration of N30-N56, N741, N743, N745, N747, U362, U363, U367, U369-U374, U389.U394, U396-U398, and U500 sweetclover genetic stocks. Forty-nine white-flowered sweetclover (Melilotus alba Medik.) genetic stocks, a yellow-flowered sweetclover genetic stock, were developed jointly by the U.S. Department of Agriculture-Agricultural Research Service and the Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln, Nebraska and were jointly released in May 2004. The genetic stocks, which contain unique combinations of genes and traits, were developed over more than three decades of cooperative sweet- clover genetic research. The development of 16 lines involved both annual and biennial forms of M. alba, and the greenhouse conditions under which seed of these lines were produced did not permit distinguishing between these forms. U389 is an annual line that was derived from a single plant of the introduction, P1165554, mentioned above. All of the other U-numbered lines were developed following treatment of U389 seed with ethyl methanesulfonate. Seed should be scarified before planting. It is requested that appropriate recognition be made if these genetic stocks contribute to research or the development of a new breeding line or cultivar.