caa a22 4500 477135366 CHVBK 20180405111716.0 cr unu---uuuuu 170330e19970501xx s 000 0 eng 10.1023/A:1002918008679 doi (NATIONALLICENCE)springer-10.1023/A:1002918008679 Genotype by environment effects and selection for drought tolerance in tropical maize. I. Two mode pattern analysis of yield [Elektronische Daten] [Scott Chapman, José Crossa, Gregory Edmeades] Ten trials evaluated the performance of several late tropical maize populations (La Posta Sequía, Pool 26 Sequía and Tuxpeño Sequía) selected for tolerance to drought during flowering and grain filling and also for yield potential. Families (S1 or full-sib) had been selected recurrently for six to eight years on an index of traits. Pattern (clustering and ordination) analysis was used to analyse the relative performance of entries that included cycles of selection for drought tolerance in the populations and non-drought tolerant checks. Mean environment (E) yields ranged from 1.0 to 10.4 t ha-1. Analysis of variance showed that 97.9% of the total sums of squares was accounted for by E, and that, of the remaining sums of squares the G × E (genotype by environment interaction) was almost 3 times that of the contribution of G alone. Cluster analysis separated the checks, the earlier maturing drought tolerant entries and the later maturing drought tolerant entries. This was verified by principal component (PC) analysis of the G × E matrix. Grouping of the environments (i.e. based on entry performance), resulted in the separation of different types of droughts, and of medium and high yielding well-watered environments. The patterns of discrimination observed indicated that the yield gains under drought would have been unlikely to occur if selection had been done only in well-watered environments. Within each population, selection improved broad adaptation (higher mean yield) to both drought and well-watered environments and cycles of selection ‘jumped' from non-drought-tolerant to drought-tolerant groups as their specific adaptation to drought environments increased. Kluwer Academic Publishers, 1997 water stress nationallicence breeding nationallicence adaptation nationallicence G × E nationallicence clustering nationallicence ordination nationallicence Zea mays nationallicence corn nationallicence maize nationallicence Chapman Scott The Maize Program, CIMMYT, Lisboa 27, Col. Juaréz, A.P. 6-641, 06600, México D.F., México aut Crossa José CSIRO Tropical Agriculture, 4067, St. Lucia, QLD, Australia aut Edmeades Gregory CSIRO Tropical Agriculture, 4067, St. Lucia, QLD, Australia aut Euphytica Kluwer Academic Publishers 95/1(1997-05-01), 01-09 0014-2336 95:1<01 1997 95 10681 https://doi.org/10.1023/A:1002918008679 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1002918008679 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Chapman Scott The Maize Program, CIMMYT, Lisboa 27, Col. Juaréz, A.P. 6-641, 06600, México D.F., México aut NATIONALLICENCE 700 1- Crossa José CSIRO Tropical Agriculture, 4067, St. Lucia, QLD, Australia aut NATIONALLICENCE 700 1- Edmeades Gregory CSIRO Tropical Agriculture, 4067, St. Lucia, QLD, Australia aut NATIONALLICENCE 773 0- Euphytica Kluwer Academic Publishers 95/1(1997-05-01), 01-09 0014-2336 95:1<01 1997 95 10681 Metadata rights reserved Springer special CC-BY-NC licence nationallicence SWISSBIB 477135366 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer