II. 20. Autotetraploids: Field performance of tetraploid and corresponding diploid stocks.
W. Friedt, Biologische Bundesanstalt fur Land- und Forstwirtschaft, Institut fur Resistenzgenetik, GrUnback, D-8059 Bockhorn, Federal Republic of Germany.
As anticipated in BGN 11 (Friedt, 1981), the collection of tetraploid barley was grown again at Grünbach in 1981 for seed multiplication. Afterwards, 10,000 seeds of each pure-breeding stock were transferred for longterm storage to the German Genebank, Institut fur Pflanzenbau und Pflanzenzüchtung (FAL), D-3300 Braunschweig-Völkenrode (FRG). However, limited amounts of seed can still be requested from our Institute.
A list of available, pure stocks is given below (Table 1). Therein, also the grain yield as determined in single drill plots is given. The yield data are summarized in Figure 1, where the frequency distributions for grain yield of autotetraploid and original diploid parents are compared. It is evident that the yield of the former is generally much lower than that of the latter, although some of the older diploid stocks are comparatively poor yielding. Even the highest yielding tetraploids, i.e. Nos. 629, 630, 632 and 641, did not yield more than 50-60% of the best diploid parent (No. 470).
Table 1. Collection of tetraploid barley.
Diploid parents, field no. 401-430 (p. 50)
Diploid parents, field no. 431-460 (p. 51)
Diploid parents, field no. 461-486 (p. 52)
Autotetraploids, field no. 501-529 (p. 53)
Autotetraploids, field no. 531-566 (p. 54)
Autotetraploids, field no. 567-601 (p. 55)
Autotetraploids, field no. 602-636 (p. 56)
Autotetraploids (637-651), 6-rowed, 2-rowed
(p. 57)
Tetraploid selected strains (p. 58)
In a separate experiment, the yield performance of several tetraploid and diploid stocks was compared more accurately; the results are presented in Table 2. As a rule, the yield of autotetraploids is less than half that of corresponding diploid parents. This immense yield reduction is mainly due to the partial sterility but also to the reduced tillering of autotetraploids as compared to parental diploids (Friedt, 1978). In a longterm breeding programme it was tried to improve fertility and vigour of tetraploid barley. This was partially successful with regard to fertility (Friedt, 1978). However, tetraploid stocks selected for high fertility after repeated mutagenic treatment and multiple hybridization still show approximately the same yield as the original autotetraploids (see end of Table 1, Nos. 6032, 6136).
References:
Friedt, W. 1978. Untersuchungen an autotetraploiden Gersten unter besonderer
Berucksichtigung der Diploidisierung. I. Fertilitat, Vitalitat und Kornertrag.
(Investigations in autotetraploid barley with special reference to its
diploidisation. I. Fertility, vigour and kernel yield). Z. Pflanzenzuchtg.
81:118-139.
Friedt, W. 1981. Autotetraploids. (Coordinator's report) BGN 11:90-95.
