Effects of a rice major gene Ur1 (Undulate rachis ‐1) on panicle and grain traits. Issue 4 (9th September 2014)

• Record Type: Journal Article
• Authors: Murai, Masayuki; Hata, Toru; Kosumi, Tomohiro; Seike, Hirotaka
• Is Part Of: Hereditas. Volume 151:Issue 4/5(2014)
• Page Start: 61
• Page End: 72
• Publication Date: 2014-09-09
• Subjects: Heredity -- Periodicals; Genetics -- Periodicals; Cytogénétique; Génétique; Hérédité; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 576.5
• DOI: 10.1111/hrd2.02280
• Languages: English
• ISSNs: 0018-0661

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>A rice dominant gene, <italic>Ur1</italic>, increases spikelet number per panicle, thereby enlarging sink size. The effects of <italic>Ur1</italic> on panicle and grain traits were examined using 'Nishihikari' (N), its <italic>Ur1</italic> isogenic line (N<sup>U</sup>) and their F<sub>1</sub>, and the <italic>sd1‐d</italic> isogenic line of Taichung 65 (d), the <italic>sd1‐d‐Ur1</italic> isogenic line (u) and their F<sub>1</sub>. <italic>Ur1</italic> increased number of primary branches per panicle (NB1), number of secondary branches per primary branch (NB2) and number of spikelets per single secondary branch (SB2). Increase in NB1 was higher in N<sup>U</sup> than in u but those in NB2 and SB2 were lower in N<sup>U</sup> than in u, all of which brought about a lower percentage of secondary‐branch spikelets for N<sup>U</sup>. Regarding secondary‐branch spikelets as well as whole spikelets, N<sup>U</sup> had a higher ripened‐grain percentage caused by its higher fertilized‐spikelet percentage than u. The above characteristics of N<sup>U</sup> contribute to its high yielding ability, suggesting that N is a favorable genetic background for <italic>Ur1</italic>. In addition, number of differentiated (developed + degenerated) secondary branches per primary branch and presence of twined spikelets in the uppermost primary branch of a panicle could be new indicators to discriminate <italic>Ur1/Ur1</italic> plants from <italic>Ur1/+</italic> and +/+ plants in a segregating population like an F<sub>2</sub>.</p> </abstract>