DETERMINATION OF RUST RESISTANCE GENES IN PAKISTANI BREAD WHEATS

Abstract

Stripe and leaf rusts are the major constraints to bread wheat production in Pakistan. Molecular markers were used to investigate the presence of leaf rust and stripe rust resistance gene cluster Lr34/Yr18 and stem rust resistance gene Sr2 in 52 Pakistani bread wheat cultivars/lines. PCR amplification of DNA fragments using DNA marker csLV-34 showed that 13 of the studied cultivars/lines, namely ‘03FJ26’, ‘NR 337’, ‘NR 339’ ‘NR 347’, ‘NR 350’, ‘Manthar’, ‘Margalla 99’, ‘Iqbal 2000’, ‘Saleem 2000’, ‘Wafaq 2001’, ‘Marwat 2001’, ‘Pirsabak 2004’ and ‘Fareed 2006’ carry leaf rust and stripe rust resistance genes Lr34/Yr18. Stem rust resistance gene Sr2 was observed in 36 Pakistani spring wheat cultivars/lines using stm560.3tgag marker. The slow rusting gene Sr2 needs to be combined with additional stem rust resistance genes to establish durable resistance against Ug99 in modern wheat cultivars. Low frequency of Lr34/Yr18 was found in Pakistani wheats. This gene cluster needs to be incorporated into Pakistani wheats for durable rust resistance.