the Symposium on Wheats for More Tropical Environments - cimmyt

129The introduction of alien geneticmaterial affecting physiological traits of<strong>the</strong> recipient species is free from thisrestriction; this is a static system.Consequently, manipulationsintroducing material of this type have<strong>the</strong> potential of producingbreakthroughs in commercialproduction. It would be anticipated, forexample, that, ifit is possible tointroduce genetic material providingdrought resistance or tolerance, highprotein content, protein quality, salttolerance or various metal tolerances, itwould allow <strong>the</strong> cultivation of wheat inareas where it is currently impossible.As <strong>the</strong> demands for increased worldfood production increase, <strong>the</strong> value ofintroduced variation will also increase.It is not possible to predict <strong>the</strong> futuregenetic demands that may be placed onwheats as new races of pathogensappear or as cultivation is extended intonew areas. Consequently, a stock ofalien genetic material introduced fromwide hybrids may prove to be of greatvalue.It appears that <strong>the</strong> use of wide hybridsand <strong>the</strong> derived genetic material in <strong>the</strong>Triticeae will provide an expandingsource of genetic variation for plantbreeders which, in some cases, mayeven amount to quantum changes inei<strong>the</strong>r <strong>the</strong> production or distribution of<strong>the</strong> crop.Reference1. Mujeeb-Kazi, A., and G. Kimber.The production, cytology andpracticality of wide hybrids in <strong>the</strong>Triticeae. (In preparation.)