The Potential of Iranian Landraces in Wheat Breeding Programs.

Wheat landrace accessions have the potential to add diversity to breeding programs providing resistance and tolerance to biotic and abiotic stresses.  A subset of 57 accessions from the Iranian landrace collection was obtained from the National Small Grains Collection (NSGC). The accessions were phenotyped and/or genotyped for resistance to root lesion nematode (RLN) species Pratylenchus neglectus and P. thornei as well as stripe rust, growth habit, days to heading, photoperiod sensitivity, kernel hardness and color, height and other traits. The RLN screens indicate 30 accessions have resistance to both nematode species that is better than the current resistant standards.  Stripe rust greenhouse trials using race PST 100 indicates that two accessions possess seedling resistance.  Three additional accessions were rated as moderately resistant under natural inoculation in the field.  Spring habit was the dominant growth type in the subset with only two accessions possessing winter habit.  The spring lines averaged 61 days to heading in the field and an average height of 91mm.   The Vrn-B1a spring allele was the most common, present in 31 accessions, with the Vrn-D1a present in 15 of the accessions.  All of the accessions possessed the ppd-D1b allele for photoperiod sensitivity.  Kernel color characterization showed 20 accessions are red, 6 white and 31 an intermediate tan.  Single kernel characterization indicates that grain of 18 accessions is either hard or mixed class and two accessions are super soft while all others are soft.  Other traits observed were pubescence of the leaves and heads in 12 accessions and awnless head types in three accessions.  The NSGC database shows 12 accessions in the subset have resistance to common bunt and 5 are resistant to Russian wheat aphid.  The diversity in this small subset indicates that the Iranian landrace collection has the potential to be a valuable resource to breeding programs.