Hockett TABLE 4 Broad and Narrow Sense Heritability and Genetic Advance Estimates for Grain Yield Components and Other Agronomic Characteristics Since 1964 Heritability" Broad sense Narrow sense Genetic advanceb Number Number Number Average Range references Average Range references Average Range references Characteristic (%) (%) reviewed (%) (%) reviewed (%) (%) reviewed Grain yield 44 5-93 26 27 0-54 11 23 3-46 10 Spike number 49 3-98 24 34 14-66 9 33 4-113 12 Kernels/spike 64 15-99 23 39 2-91 12 28 3-71 8 Kernel weight 63 24-99 22 43 13-78 10 12 2-22 9 Heading date 74 19-100 17 60 34-92 6 10 1-23 9 Lodging score 66 41-88 5 27 6-38 3 123 1 Plant height 66 4-99 30 41 8-73 13 15 1-44 11 Grain protein 53 5-98 14 32 8-76 4 16 5-22 3 Grain plumpness 62 34-90 5 43 24-58 3 18 11-24 2 Diastatic power Barley 82 55-94 5 58 23-94 3 20 Malt 68 50-86 2 Extract Barley 59 43-71 3 12 8-16 211 Malt 57 46-69 3 Spike length 66 3-98 17 50 44-56 5 20 4-34 8 'Computations were most often on the plot basis, but some were on a plant or trial mean basis. 'Given as percentage of the mean. Source: Ref. 15. barley [41] and have been used to produce homozygous sp. spontaneum and bulbosum have about 3000 and 600 lines and study segregation ratios and linkage values in ga-ascensions, respectively [46,47]. The locations of the ma-metes produced by F1 plants (haploids); produce aneu-jor base germplasm collections are shown in Table 5. ploids (triploids); and attempt to produce commercial, 2n = Working germplasm collections are found in Brazil, Bul-4x = 28 chromosome barleys (autotetraploids). Individual garia, the Czech Republic, England, Germany, Slovakia, pairs of barley chromosomes have been added to the chro-Syria, the Netherlands, the United States, and Russia [48]. mosome complement of wheat [41] and used to make ge-Many composite crosses of barley are maintained in the netic and evolutionary studies of barley. Figure 8 shows a United States, with CCXLVII being the last one assigned a micrograph of barley chromosomes. number by the USDA-ARS collection [49]. A new strategy to physically relate RFLP-based genetic Recent attempts have been made to set up "core" col-linkage maps with cytological markers of the barley chro-lections of barley germplasm [50,51]. Selection of these mosomes has been devised by Sorokin et al. [44]. Morpho-genotypes can be divided into four steps: (1) definition of logically distinct translocation chromosome were mi-domain, (2) division into genetically distinct types, (3) al-croisolated, and their DNA was used as a template for location of entries over types, and (4) choice of entries polymerase chain reaction with sequence-specific primers. [51]. Cross [50] has integrated both simply inherited phe-A recent review of these techniques in cereals is given by notypically obvious markers with electrophoretic patterns Kunzel and Korzun [45]. in setting up a core collection. D. Germplasm Resources 2. Wide Crosses Reviews describing the wide crosses made in barley are 1. Collections given by von Bothmer [47,52] and Fedak [53,54]. The ori-About 25,000 barley landraces plus 25,000 breeder lines gin, taxonomy, and related species of barley are described and cultivars are preserved in collections of barley [52], as are the incompatibility, mechanisms, and cytoge-throughout the world [46]. In addition, the wild H. vulgare netics of wild barley crosses [53]. There is a general lack

· 2000 · Handbook of Cereal Science and Technology, Revised and Expanded · DOI 10.1201/9781420027228-12