BGN 12: Genetic components and correlations between kernel yield, protein and amino acid content BARLEY GENETICS NEWSLETTER, VOL. 12, II. RESEARCH NOTES
Fejer et al., pp. 59-63

II. 21. Genetic components and correlations between kernel yield, protein and amino acid content of F1 crosses between five male-sterile barley cultivars and six mutants for reduced root growth and spike number.

S. O. Fejer, R. G. Fulcher and L. P. Lefkovitch, Agriculture Canada, Ottawa, Ontario K1A OC6, Canada.

In the Ottawa growth chambers, maintained at 16 hours daylength and 20°C day and 15°C night temperatures, we crossed five male-sterile cultivars from Dr. D. R. Metcalfe, Agriculture Canada, Winnipeg, Manitoba, in a 1/4 diallel (factorial) fashion -binary code 1-5 for the first digit; six-rowed Bonanza=5, Galt=2 and Keystone=l, and two-rowed Betzes=4 and Herta=3- with five derivatives of a mutant for reduced root growth -code 6-0- from Bomi (Linde-Laursen, BGN 7:43-45, 1977) and QB 58-14, a uniculm barley from Dr. H. Klinck, Macdonald College, St. Anne de Bellevue, Quebec - code 1 in the second digit.

The resulting 28 F1 progenies (two of the crosses were unsuccessful) were grown in the growth room, in 30 cm pots, three pots per progeny, and 8 agronomic traits of morphology, yield and protein content were determined in all three replicates. Further 18 chemical constituents, including lysine, lysine yield, and 16 other amino acids (Table 1) were measured or calculated for two replicates only.

Table 1. Morphological (3 reps.) and chemical (2 reps.) characters in 28 factorial crosses between 5 adapted and 6 introduced barleys

The two-rowed characteristic of Herta (Code 3) as female parent was inherited by its progeny, including the shortest plants (Codes 37-38, 75 and 77 cm), and partially balanced by higher spike numbers (Code 30, 15) also in Betzes (Code 41, 15), but the highest numbers were shown by the six-rowed Bonanza x Bomi 4 (Code 59) cross with 18 spikes, as also indicated by the general combining abilities (GCA) in Table 2.

Table 2. General combining abilities in barley factorial crosses

Without going into any further details in all characters, the main purpose of increasing lysine yield was promising success, not so much for the Bomi mutants, where the well-known Risø 1508 was not available at the time of the crossing, but because of the unexpectedly high combinations of kernel yield, protein % and lysine % of the uniculm crosses, especially with Keystone (Code 11), resulting in a lysine yield of 126 mg, and with Bonanza (Code 51), 92 mg; these crosses are now under further study. The low spike number of the uniculm parent was not expressed in the F1: all five male-sterile mother plants, and also Bomi 2 and 3 pollen parents had lower GCA values (Table 2), but it could show up in later generations. Similarly, the single recessive root growth gene of the Bomi mutations 1-5 was not manifested in petri dish tests but its effects on reduced top growth and kernel yield (Fejer, unpublished work) may have resulted in the low GCA values for kernel yield in all Bomi mutants.

Many of the other amino acids showed ranges of variation promising for further selection, similar to the findings of Robbins et al. (1971) in oats, but differing from Robbins and Pomeranz (1972) in barley, where a very small genetic sample was analysed. As the %-values were transformed for statistical analyses, confidence limits could not be attached to the untransformed means of Table 1 but all F-values for amino acids were significant at the 1% level except cystine (5% level) and histidine (not significant). Highest significances were shown by two amino acids of potential nutrient value (Robbins et al. 1971) methionine (F=8.0) and threonine (F=6.0, d.f. 27, 26).

Correlations (Table 3) between kernel yield and protein % (-13) and protein % and lysine % (-21) were negative but non-significant as demonstrated by the exceptions mentioned above. Correlations among amino acids indicated definite grouping patterns, and further work is proceeding on these lines.

Table 3. Phenotypic correlations (x 100) between 26 yield and chemical component characters (d.f. 52)

References:

Robbins, G. S., Y. Pomeranz and L. W. Briggle. 1971. Amino acid composition of oat groats. J. Agr. Food Chem. 19:536-539.

Robbins, G. S. and Y. Pomeranz. 1972. Composition and utilization of milled barley products III. Amino acid composition. Cereal Chem. 49:240-246.

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