<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Burson, B. L.</style></author><author><style face="normal" font="default" size="100%">Hussey, M. A.</style></author><author><style face="normal" font="default" size="100%">Actkinson, J. M.</style></author><author><style face="normal" font="default" size="100%">Shafer, G. S.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effect of pollination time on the frequency of 2n+n fertilization in apomictic buffelgrass</style></title><secondary-title><style face="normal" font="default" size="100%">Crop Science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">egg</style></keyword><keyword><style  face="normal" font="default" size="100%">hybridization</style></keyword><keyword><style  face="normal" font="default" size="100%">paspalum-dilatatum</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">Jul-Aug</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://000176601900002</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">42</style></volume><pages><style face="normal" font="default" size="100%">1075-1080</style></pages><isbn><style face="normal" font="default" size="100%">0011-183X</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Fertilization of an unreduced egg (2n + n) increases ploidy level and creates a new hybrid. It occasionally occurs in apomictic species but at a frequency too low to be a reliable method for genetic improvement. This investigation was undertaken to determine if 2n + n fertilization could be increased by early pollination. Six buffelgrass, Pennisetum ciliare (L.) Link [syn. Cenchrus ciliaris L.], accessions, five apomicts and one sexual, were self-pollinated and cross-pollinated with birdwoodgrass, P. ciliare (L.) Link var. setigerum (Vahl.) Leek, at 3, 2, 1, and 0 d before anthesis. The 2n + n progeny were identified by flow cytometry. DNA content (pg 2C(-1)) was determined for 1962 self-pollinated and 3072 cross-pollinated plants. Twenty-eight self-and 80 cross-pollinated plants had a higher DNA content and were products of 2n + n fertilization. The overall frequency of 2n + n fertilization when self- and cross-pollinated was 1.4 and 2.6%, respectively. For all protogynous intervals, the frequency ranged from 0 to 5.2% for self-pollinated plants and 0 to 8.2% for cross-pollinated plants. When self-pollinated, there was no correlation between time of pollination and recovery of 2n + n hybrids. When cross-pollinated, there was a linear relationship between time of pollination and number of 2n + n hybrids recovered. More 2n + n hybrids were recovered from crosses made 2 or 3 d before anthesis. Thus in apomictic buffelgrass, the frequency of 2n + n fertilization can be increased by pollinating early, and in apomictic species where sexual germplasm is not available, this approach has potential to produce new apomictic hybrids.</style></abstract><work-type><style face="normal" font="default" size="100%">Article</style></work-type><accession-num><style face="normal" font="default" size="100%">ISI:000176601900002</style></accession-num><notes><style face="normal" font="default" size="100%">ISI Document Delivery No.: 569KQTimes Cited: 7Cited Reference Count: 22Cited References: *SAS I, 1999, SAS STAT US GUID VER BASHAW EC, 1962, CROP SCI, V2, P412 BASHAW EC, 1987, PRINCIPLES CULTIVAR, V2, P40 BASHAW EC, 1990, CROP SCI, V30, P571 BASHAW EC, 1992, INT J PLANT SCI, V153, P446 BRAY RA, 1978, EUPHYTICA, V27, P801 BURSON BL, 1991, GENOME, V34, P950 BURSON BL, 1996, P 1996 AM FOR GRASSL, P226 DEWET JMJ, 1979, POLYPLOIDY BIOL RELE, P3 ESPINOZA F, 2000, INT J PLANT SCI, V161, P221 FISHER WD, 1954, AGRON J, V46, P401 HARLAN JR, 1975, BOT REV, V41, P361 HUSSEY MA, 1993, P 17 INT GRASSL C 8, P404 KINDIGER B, 1994, GENETICA, V92, P197 MARTINEZ EJ, 1994, J HERED, V85, P295 PEPIN GW, 1971, CROP SCI, V11, P445 READ JC, 1969, CROP SCI, V9, P805 SHAFER GS, 2000, CROP SCI, V40, P391 SHERWOOD RT, 1980, CROP SCI, V20, P375 SNYDER LA, 1955, BOT GAZ, V116, P209 VIELLE JP, 1995, PLANT J, V8, P309 WIPFF JK, 1995, THESIS TEXAS A M UCrop science soc amerMadison</style></notes><auth-address><style face="normal" font="default" size="100%">Burson, BLTexas A&amp;M Univ, USDA ARS, Crop Germplasm Res Unit, 430 Heep Ctr, College Stn, TX 77843 USATexas A&amp;M Univ, USDA ARS, Crop Germplasm Res Unit, 430 Heep Ctr, College Stn, TX 77843 USATexas A&amp;M Univ, USDA ARS, Crop Germplasm Res Unit, College Stn, TX 77843 USATexas A&amp;M Univ, Dept Soil &amp; Crop Sci, College Stn, TX 77843 USAYoder Bros Inc, Chualar, CA 93925 USA</style></auth-address></record></records></xml>