000 02875nab a22003617a 4500
001 G97253
003 MX-TxCIM
005 20171220113559.0
008 121211b |||p||p||||||| |z||| |
024 8 _ahttps://doi.org/10.1007/BF00028606
040 _aMX-TxCIM
041 0 _aEn
100 1 _aArntzen, F.K.
245 0 0 _aDevelopment of barley leaf rust, Puccinia Hordei, infections in barley. II. Importance of early events at the site of penetration for partial resistance
260 _c1986
500 _aPeer-review: Yes - Open Access: Yes|http://science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=MASTER&ISSN=0014-2336
520 _aThe investigation involved three barley genotypes that varied from extremely susceptible (Akka) to an extreme level of partial resistance (17-6-16). The barley leaf rust colony size was measured in primary leaves 3, 6, 12 and 18 days after inoculation and in flag leaves 6, 12, 18, 24 and 30 days after inoculation with race 1-2-1. Akka always had the largest colonies, 17-5-16 the smallest, with Vada at an intermediate position. The genotypic differences were proportionally largest at the second sampling day and smallest at the last sampling day. The rate of colony growth decreased rapidly over time for all genotypes and in both plant stages. Measured at the same time (colony age the same) the rate of colony growth was largest for 17-5-16 and smallest for Akka in most periods. The time needed to reach a given colony size showed already large differences in the very early states especially in the flag leaves. Akka took 3.9 days to reach a size of 17 × 10-3 mm2 (only 5 to 10% of the colony size at the start of sporulation), Vada needed 8.3 days and 17-5-16 even 12.0 days. To reach a size of 320 × 10-3 mm2 the three genotypes needed 12.7, 18.0 and 22.8 days respectively, differences that are only slightly larger than those at the very small colony size. It was concluded that the partial resistance of barley to barley leaf rust is not primarily due to a reduced fungal growth in the partially resistant host tissue but predominantly so to an initial and temporary stagnation at the site of penetration. The longer this stagnation lasts, the longer the latent period and the higher the partial resistance are. Once this stagnation has been overcome the fungal growth rates do not vary much between genotypes with different levels of partial resistance.
546 _aEnglish
591 _aSpringer
593 _aCarelia Juarez
595 _aRPC
650 1 0 _aBarley
_91018
650 1 0 _aBarley leaf rust
650 1 0 _aColony size
650 1 0 _aHordum vulgare
650 1 0 _aInitial stagnation
650 1 0 _alatent period
650 1 0 _aPartial resistance
650 1 0 _aPuccinia hordei
700 1 _aParlevliet, J.E.,
_ecoaut.
773 0 _tEuphytica
_gv. 35, no. 3, p. 961-968
942 _cJA
999 _c29581
_d29581