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Agronomic Comparisons among Wheat Lines Nearly Isogenic for Three Reduced‐Height Genes 1
Author(s) -
Allan R. E.
Publication year - 1986
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/cropsci1986.0011183x002600040014x
Subject(s) - tiller (botany) , biology , gene , yield (engineering) , line (geometry) , grain yield , horticulture , agronomy , zoology , genetics , mathematics , physics , geometry , thermodynamics
The two most commonly used reduced‐height genes of wheat ( Triticum aestivum L.) are Rht 1 , and Rht 2 . The Rht 3 , gene is known to be a potent height‐reducing gene. Information is limited as to the comparative effects of these three genes on agronomic traits, especially when placed in a common genetic background. This study made multiple site‐year comparisons in Washington for grain yield, plant height, volume weight, kernel weight, and tiller number among five reduced‐height, near‐isogenic lines and their recurrent parent, ‘Burt’. One line had the Rht 3 , gene. One line each had the Rht 1 , and Rht 2 , genes combined from ‘Norin 10’ and from ‘Suwon 92’. One line each had either the Rht 1 or Rht 2 , gene separately from these two sources. Plant heights of lines with either Rht 1 , or Rht 2 , alone, Rht 1 , and Rht 2 , combined, and with Rht 3 , were reduced 24, 52, and 64%, respectively. The Rht 3 , line had the lowest ( P <0.05) across‐test mean yield of 3360 kg ha −1 . The two lines with both Rht 1 , and Rht 2 , exceeded ( P <0.05) the yield of the Rht 3 , line with means of 3660 and 3840 kg ha −1 ; these values were less ( P <0.05) than the Burt mean yield of 4440 kg ha −1 as well as the yields (4300 and 4900 kg ha −1 ) of lines with either Rht 1 or Rht 2 . The Suwon 92 derived line with either Rht 1 or Rht 2 , exceeded ( P <0.05) the mean yields of other lines and Burt by 10 to 46%. The Rht 3 line had significantly lower ( P <0.05) mean volume weight, kernel weight, and tiller number than the other lines and Burt. Reductions in these traits of the Rht 3 line compared to Burt were 11, 31, and 11% respectively. Lines with one or both Rht 1 and Rht 2 , genes had lower ( P <0.05) kernel weights than Burt. All Rht genes reduced volume weight. Although Rht 3 , is an effective height‐reducing gene, it caused negative effects on yield, volume weight, kernel weight, and tiller number. Single dosages of Rht 1 , or Rht 2 , caused neutral or positive effects on yield and tiller number, and warrant use in breeding.