000 03709nam a22005657a 4500
001 G80103
003 MX-TxCIM
005 20250211163013.0
008 121211s ||||f| 0 p|p||0|| |
020 _a970-648-120-6
040 _aMX-TxCIM
072 0 _aF30
072 0 _aH10
090 _aCIS-4174
110 0 _aCentro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) Kenya
100 1 _aHearne, S.
_gGenetic Resources Program
_gDG's Office
_8INT3287
_9912
245 0 0 _aTransposons and tolerance; teh identification of genes for Striga tolerance in maize
260 _aNairobi (Kenya)
_bKARI*CIMMYT :
_c2002
300 _ap. 173
340 _aPrinted
500 _aAbstract only
520 _aStriga is one of the most severe constraints to cereal production in areas of the semi-arid tropics of Africa where subsistence agriculture is predominant. The development of Striga tolerant or resistant germplasm has been the goal of many maize breeders. However, to date, no resistant maize has been developed and tolerance, though improved, is still limited. Funded by the Rockefeller Foundation, we developed a large population of maize which contained transposable element-induced mutations. The transposon selected was the mutator element system. Mutator elements preferentially insert into coding regions of the genome and are therefore optimal for transposon-tagging. 8000 F2 families from the transposon-tagged maize population were screened in the field in Kibos during 1 998 and 1999. Interesting families were identified as those which had segregating Striga-free plants (no emergence) within the family. Twenty three families have been identified which have no/low emergence of Striga. All these families displayed 1:3 segregation for the Striga free trait (25% Striga free, 75% Striga emergence), this indicates that a single recessive mutation is responsible for the observed phenotype. The progeny of one of these families has been screened in pot experiments in the laboratory and the phenotype observed in the field has been confirmed. The lack of Striga emergence was not due to altered germination stimulant production or perturbed attachment. However, the biomass of the parasite on this transposon-tagged line was much lower than that on susceptible control lines. As such the growth of Striga attached to the transposon-tagged plants was severely impaired resulting in a low incidence of emergence. Work is currently underway to: develop molecular markers to aid in the introgression of this trait into other maize lines; to clone and identify the gene underlying the trait; to investigate the physiological basis of Striga growth retardation and to; evaluate other interesting maize families in the laboratory.
536 _aConservation Agriculture Program|Genetic Resources Program
546 _aEnglish
591 _a0409|AGRIS 0401|AL-Maize Program
593 _aJuan Carlos Mendieta
594 _aINT3287|INT2340
595 _aCSC
650 1 0 _aAngiosperms
650 1 0 _91897
_aBiomass
_gAGROVOC
650 1 0 _aInfestation
650 1 7 _aMaize
_gAGROVOC
_2
_91173
650 1 0 _91195
_aParasitic plants
_gAGROVOC
650 1 0 _aPest control
650 1 0 _aStriga hermonthica
650 1 0 _aTripsacum
653 0 _aCIMMYT
653 0 _aKARI
700 1 _aFriesen, D.K.|Palmer, A.F.E.
700 1 _aGrimanelli, D.,
_ecoaut.
700 1 _aGurney, A.L.,
_ecoaut.
700 1 _aHoisington, D.A.,
_ecoaut.
700 1 _aKanampiu, F.K.,
_ecoaut.
700 1 _aMbogo, P.O.,
_ecoaut.
700 1 _aOdhiambo, G.D.,
_ecoaut.
_9628
700 1 _aPress, M.C.,
_ecoaut.
700 1 _aScholes, J.D.,
_ecoaut.
700 1 _aVasey, R.,
_ecoaut.
942 _cPRO
999 _c7333
_d7333