This article was downloaded by: [200.129.254.1] On: 21 July 2011, At: 07:40 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK New Zealand Journal of Agricultural Research Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tnza20 Selection of morphological traits to improve forage characteristics of Setaria sphacelata grown in Florida L. Jank a , K. H. Quesenberry b , L. E. Sollenberger b , D. S. Wofford b & P. M. Lyrene c a Embrapa Beef Cattle, CxP.154, MS, Campo Grande, CEP 79002–970, Brazil E-mail: [email protected] b Agronomy Department, University of Florida, Gainesville, Florida, USA c Horticultural Sciences Department, University of Florida, Gainesville, Florida, USA Available online: 22 Feb 2010 To cite this article: L. Jank, K. H. Quesenberry, L. E. Sollenberger, D. S. Wofford & P. M. Lyrene (2007): Selection of morphological traits to improve forage characteristics of Setaria sphacelata grown in Florida, New Zealand Journal of Agricultural Research, 50:1, 73-83 To link to this article: http://dx.doi.org/10.1080/00288230709510284 PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions This article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, re-distribution, re-selling, loan, sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. Downloaded by [200.129.254.1] at 07:40 21 July 2011 New Zealand Journal of Agricultural Research, 2007, Vol. 50: 73-83 73 0028-8233/07/5001-0073 © The Royal Society of New Zealand 2007 Selection of morphological traits to improve forage characteristics of Setaria sphacelata grown in Florida L.JANK suited to Florida with improved yield and quality Embrapa Beef Cattle providing they tolerate winter cold and reliably CxP.154 produce seed. CEP 79002-970 Campo Grande MS, Brazil Keywords breeding; leaf width; inflorescence [email protected] number; forage production; forage quality K. H. QUESENBERRY L. E. SOLLENBERGER INTRODUCTION D. S. WOFFORD Agronomy Department The forage grass Setaria sphacelata (Schumacher) University of Florida Moss (setaria) has been widely used in medium Gainesville, Florida, USA rainfall subtropical regions as a pasture grass for grazing of dairy and beef cattle, as well as for silage P. M. LYRENE and hay. The species has been recommended for use Horticultural Sciences Department in tropical and subtropical countries with a mini- University of Florida mum yearly rainfall of 750 mm, or 580 mm on very Gainesville, Florida, USA fertile soils (Botha 1948). However, it grows better in wetter areas with no prolonged dry season (Rat- tray 1960), as in the wet zone of Sri Lanka (Assefa Abstract A genetically diverse population of & Premaratne 1990), on dairy farms in the humid Setaria sphacelata was developed at Gainesville, tropics of Costa Rica (Sanchez et al. 1998), and in Florida by intercrossing the cultivars 'Narok', 'Ka- Thailand (Hare et al. 1999). Animal performance on zungula' and 'Solander' and a local persistent popu- setaria pastures can be limited by low rainfall (Jones lation. To determine heritability of traits that may & Evans 1989). improve setaria as a forage plant in Florida, progeny Setaria has the desirable forage attributes of high of the intercrossed population underwent two cycles yield (Singh et al. 1995), persistence (Gibson & Downloaded by [200.129.254.1] at 07:40 21 July 2011 of selection for inflorescence number and one cycle Andrews 1985), high crude protein concentration for leaf width. The selected populations, together (Almeida & Flaresso 1991) and good animal per- with cultivars and introductions, were evaluated for formance (Jones & Evans 1989). In southern Brazil, morphological characters, yield and forage quality 'Narok' setaria was superior to Hemarthria altissima in field experiments with close- and wide-spaced for milk production (Martinez 1993), and in Mexico, plants. Increase of inflorescence number was not meat production on 'Kazungula' setaria was higher obtained by selection but resulted in decreased plant than on Brachiaria brizantha pastures (Partida et al. height, inflorescence length, yield, leaf width, and 1983). Recent evaluations have shown that setaria leafiness. Leaf width was increased by selection may have forage potential in Florida particularly if and was associated with increased leafiness and selections can be made to ensure winter survival whole-plant crude protein content. The results sug- (Jank et al. 2002). gest good prospects for selection of setaria cultivars Setaria sphacelata is a polyploid complex rang- ing from diploid to decaploid (Hacker 1968). The basic chromosome number is n = 9. It includes the varieties sphacelata, aurea (A. Br.) Clayton, torta A06037; Online publication date 2 March 2007 (Stapf) Clayton, sericea (Stapf) Clayton, and splen- Received 7 June 2006; accepted 17 November 2006 dida (Stapf) Clayton (Clayton & Renvoize 1982). 74 New Zealand Journal of Agricultural Research, 2007, Vol. 50 There is no clear morphological distinction between The objectives of this research were to produce these varieties and they readily intercross (Hacker advanced populations of S. sphacelata selected for 1968). Of the released cultivars, only 'Nandi' (var. morphological traits of agronomic value and to sericea) is diploid (Hacker 1966). All the others, evaluate the effects of this selection on agronomic 'Kazungula' and 'Narok' (var. sericea) and 'Solan- performance in a common environment. Specific der' and 'Splenda' (crosses between var. sericea and objectives were to increase dry matter yield through var. splendida) are tetraploid (Hacker 1966; Oram selection of wider leafed populations, and increase 1986). seed production through selection of higher inflo- Setaria is largely cross-pollinating and apomixis rescence number populations. has not been reported. Favoured by self-incompat- ibility, random mating of inflorescences from se- lected parents has been successful when combined with multiple recurrent selection cycles to enhance MATERIALS AND METHODS the process of plant improvement (Jank et al. 2002). Early breeding focused on S. sphacelata var. sericea Base population for traits such as forage yield, seed yield and frost A population of S. sphacelata with a wide genetic tolerance (Jank & Hacker 2003). Later, var. splen- base was planted in August 1996 at the Agronomy dida was incorporated into the breeding programmes Forage Research Unit (AFRU) of the University because it is more robust than var. sericea and has a of Florida, near Gainesville, Florida (29°75 N, higher number of culm nodes, greater culm diameter, 82°4 W). Two thousand seedlings were planted on wider leaves and is taller and later flowering. The 90 cm centres. The population was a bulk of seeds only negative aspects of this introduction was its from 'Narok', 'Kazungula', and 'Solander' and from almost complete sterility (Hacker 1985). Since then, roadside plants that had persisted for many years improved seed production was the focus of many at the University of Florida Range Cattle Research breeding programmes (Wijk 1980; Hacker 1991a,b; and Education Center at Ona, Florida. 'Narok' and Hacker &Cuany 1997). 'Solander' were selected in Australia for frost toler- High heritabilities were found for leaf width ance and are recommended for subtropical areas. (Hacker & Bray 1981), inflorescence length, and til- 'Kazungula' was selected in South Africa for graz- ler fertility (Hacker & Cuany 1997), suggesting that ing and hay production and is indicated for more these traits can be easily selected. Wide leaves may tropical areas (Jank & Hacker 2003). This cultivar increase sward density and thus may increase short- is the most widely grown one and the most drought term intake by cattle. Inflorescence length and tiller tolerant. It is very productive in summer, but this fertility may increase seed production. Leaf width is associated to high stem and seed production. was positively correlated with flower inflorescence 'Narok' and 'Solander' are leafier than 'Kazungula' number and with dry weight. Selection for increased and retain green leaf after light frosts. Seed yield of dry matter yield should result in earlier flowering 'Solander' is twice that of'Narok' because of double Downloaded by [200.129.254.1] at 07:40 21 July 2011 plants with shorter inflorescences (Hacker & Bray the tiller fertility and number of heads, but still less 1981). than 'Kazungula' (Jank & Hacker 2003). A breeding programme of S. sphacelata was In autumn of 1996, grid selection for autumn developed in Gainesville, Florida since 1996, to vigour was applied to this population. The two or establish the use of this plant for forage production three most vigorous plants in each 25-plant block in the State. A base population was developed from (five rows of five plants) were selected to provide a bulk of seeds of introduced cultivars and a local 200 plants (Fig. 1). Two inflorescences per selected persistent population, and was evaluated to ensure plant were harvested when they were fully extended persistence in Florida. The key factor, tolerance of and before flowers opened to show stigmas or sta- winter cold, was assessed and proved possible to mens. The inflorescences were cut from the base be improved (Jank et al. 2002). Persistence under of the 200 selected plants with roots attached and grazing in Florida conditions was also ascertained placed together in a bucket of water in a green- (Paul Mislevy pers.