Experiments with Semidwarf Wheats in Kansas

Abstract

Kansas wheat breeding research since 1949 has indicated that twogene semidwarf wheats are not well adapted to Kansas conditions, primarily because of severe lodging. One-gene semidwarfs may be useful, but they often have lower test weight, lighter kernel weight, and lodge more than hard red winter wheat cultivars used as parents. O*er characteristics such as disease resistance, maturity, and quality can be successfully bred into the semidwarf types. IXtroduction The productiveness of semidwarf cultivars of wheat has stimulated much interest in their development throughout the world. Highest farm yields recorded have been from new semidwarf wheats grown under irrigation and heavily fertilized. (State of Washington, 170 bushels per acre in 1964 and 209 bushels in 1965, Reitz, 1968.) Short type wheats were Srst grown commercially in Japan and Italy. Short cultivars were introduced from Japan into the United States in the late 1940's by S. C. Salmon; and the first published report in the United States was by RTogel et v1., (1956). Other reports and reviews are available, i.e., McNeal et dl., (1960); Vogel et v1., (1963); Porter et d1., (1964); Johnson et v1., (1966); Briggle and Vogel, (1968); Reitz, (1968); and Reitz and Salmon, (1968) . World wide use of short types has been advanced through the research project of Rockefeller Foundation in Mexico (Borlaug, 1968). A breeding program to develop semidwarf cultivars was initiated in Kansas in 1949, using Norin 10, PI 156641, and Norin 66, PI 155276; later other sources of short germplasm were crossed with adapted cultivars. To date no satisfactory types have been selected in Kansas. The major diiculty has been lodging of the short types under either stress conditions or high fertilization and moisture. This response does not agree with results in the Pacific Northwest or with semidwarf spring wheat cultivars developed in Mexico. Experiments with Semidwarf Wheats in Kansasl This content downloaded from 207.46.13.189 on Thu, 04 Aug 2016 04:13:42 UTC All use subject to http://about.jstor.org/terms 148 Transactions of the Kansas Acvdemy of Scienre Reasons for the inconsistent results in Kansas are not known but, generally, one-gene semidwarfs and especially two-gene semidwarfs have lighter kernels and lower test weight (Reddi et al., 1969 and Malott, 1970), than standard height segregates from a cross. They also tend to lodge more under certain environmental conditions. This lodging is characterized by straw breakage at the top node at or just before . . . comblne-rlpe. A few of the many crosses and their progenies studied in Kansas since 1949 are presented here. Materials and Methods One of the original crosses was Norin 10/Pawnee. Backcrosses were made to Pawnee) an adapted cultivar, with intense selection for agronomic traits between backcrosses. Selections of the cross Norin 10/5*Pawnee, which are theoretically 15/16 Pawnee, and selections from the cross NorIn 10/3tPawnee//2*Kaw, which are 3/4 Kaw, were studied. Designation of pedigrees follows the system of Purdy et 1. (1968). More than 1100 F3 plant progenies were studied in 1966 and 1967 (Reddi et dl., 1969) and 36 in 1968 and 1969 (Malott) 1970). Only four were studied in 1970. Other material reported here involves crosses of Triumph, Parker, Bison, BlueJacket, Ottawa, and Ponca with Norin 107 Norin 16, and Seu Seun. Scout and Triumph 64 were additional standard cultivars tested. Yield, test 7eight and kernel weight were obtained from regular nursery trials. Harvested plot size was 16 or 19 2 square feet, each replicated four times in a randomized complete block design. Data were obtained from Hutchinson and Manhattan during 1967-70, and from Garden City and Hays in 1968. About 50 pounds of P205 was applied per acre to the soil at Hutchinson and Manhattan. In 1968, 1969, and 1970 about 10 pounds of nitrogen was applied per acre the previous fall at Manhattan. In 1968 and 1970, both Manhattan and Hutchinson, about 100 pounds of nitrogen was applied in the spring on half of each plot. The test was irrigated and 50 pounds of nitrogen added at Garden City in 1968. The test at Hays was fertilized with a fall application of 30 pounds of N. Results Segregation for height indicated two probable main genetic factors for height with Norin 10 crosses (Reddi et 41., 1969). This agrees with the findings of Allan and Vogel (1963). The two-gene semidwarf lines were easily identified as were one-gene semidwarfs in most cases. There are two theoretically different one-gene semidwarf genotypes but all appeared the same. Allan (1971) has developed tester stocks to identify This content downloaded from 207.46.13.189 on Thu, 04 Aug 2016 04:13:42 UTC All use subject to http://about.jstor.org/terms Experi11tents with Semiduarf Wheats in Kansas 149 the two different one-gene dwarfs. Fig. 1 illustrates two-gene, one-gene, and standard heights expressed at Hutchinson in 1969.