Reduced height genes and their importance in winter wheat cultivars grown in southern Russia

Reduced height genes are the genetic basis of the “green revolution”. Two agronomically important gibberellic acid (GA)-insensitive genes, Rht-B1b (Rht1) and Rht-D1b (Rht2), localised on chromosomes 4BS and 4DS, respectively, and the GA-responsive gene Rht8, localised on chromosome 2DS, were introduced into many cultivars worldwide. An alternative GA-insensitive gene Rht-B1e (=Rht11) was introduced into Russian wheat cultivars. In this study, we investigated the importance of Rht-B1b, Rht-B1e, Rht-D1b and Rht8 in south Russian bread wheat cultivars. The cultivars were divided into five groups: (1) Rht8c; (2) Rht-B1b; (3) Rht-B1b, Rht8; (4) Rht-B1e, Rht8; and (5) Rht-D1b, Rht8. In the Krasnodar region of south Russia 3,222,321 ha were evaluated for estimating the commercial value of each of these genes in 2009–2011. The results showed that coupling Rht-B1e with Rht8 or Rht-B1b with Rht8 was more successful compared with the effects of other genes or their combinations. The average yield of cultivars carrying Rht-B1e exceeded the average yield of cultivars from the other groups. Our study demonstrates that Rht-B1e can be recommended for use in breeding programs and the presence of a molecular marker for this allele simplifies its transfer to elite wheat germplasm.