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Relationship between Loose Smut Infection in Embryos and Adult Plants of Barley 1
Author(s) -
Rasmusson D. C.,
Mumford D. L.
Publication year - 1961
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1961.0011183x000100050030x
Subject(s) - biology , library science , computer science
'T'HE embryo test, described by Simmonds (5) and JPopp (3) is now widely used in Canada and in the malting barley area of the upper Midwest to combat loose smut of barley caused by Ustilago nuda (Jens.) Rostr. The test involves extraction and examination of the embryos of barley seeds to detect infection by U. nuda. In Canada the test serves as a criterion for accepting or rejecting barley seed for registration (4). In Minnesota and North Dakota the test is used to determine the percentage of embryos infected with loose smut in commercial seed lots. The embryo test makes it possible to obtain information on a variety's smut reaction without growing progenies of inoculated plants, resulting in a considerable saving in time and labor. Good agreement has been reported between the incidence of loose smut in barley embryos and in adult plants (3). Accordingly the feasibility of using the embryo test in identifying sources of resistance was investigated. Six varieties of barley, reported to be resistant to loose smut, Jet, Valki, C.I. 3694, Trebi, Anoidium, and Ogalitsu, along with the susceptible varieties, Colsess and Newal, were inoculated with Ustilago nuda. Inoculations were made in the field at anthesis by piercing the lemma with tweezers carrying smut spores. The inoculum was obtained by increasing the smut from a single infected barley spike collected in the field. Inoculated seeds of each variety were divided into equal subsamples. One sample was embryo tested as described by Kavanagh and Mumford (2) while the other sample was grown in the greenhouse to determine the percentage of adult plants having smutted heads. For each variety the percentage of infected embryos and smutted adult plants was based on at least 200 kernels and plants, respectively. The percentage of infected embryos and smutted adult plants is given in Table 1. Infected embryos were found in all varieties inoculated. The percentage of smutted plants corresponded closely to the percentage of infected embryos in the susceptible varieties, Newal and Colsess. This was not true of the resistant varieties. No smutted heads were produced by 5 of the 6 resistant varieties while in the other, 5% of the plants had smutted heads. The