Development and Characterization of a Psathyrostachys huashanica Keng 7Ns Chromosome Addition Line with Leaf Rust Resistance

Abstract

The aim of this study was to characterize a Triticum aestivum-Psathyrostachys huashanica Keng (2n = 2x = 14, NsNs) disomic addition line 2-1-6-3. Individual line 2-1-6-3 plants were analyzed using cytological, genomic in situ hybridization (GISH), EST-SSR, and EST-STS techniques. The alien addition line 2-1-6-3 was shown to have two P. huashanica chromosomes, with a meiotic configuration of 2n = 44 = 22 II. We tested 55 EST-SSR and 336 EST-STS primer pairs that mapped onto seven different wheat chromosomes using DNA from parents and the P. huashanica addition line. One EST-SSR and nine EST-STS primer pairs indicated that the additional chromosome of P. huashanica belonged to homoeologous group 7, the diagnostic fragments of five EST-STS markers (BE404955, BE591127, BE637663, BF482781 and CD452422) were cloned, sequenced and compared. The results showed that the amplified polymorphic bands of P. huashanica and disomic addition line 2-1-6-3 shared 100% sequence identity, which was designated as the 7Ns disomic addition line. Disomic addition line 2-1-6-3 was evaluated to test the leaf rust resistance of adult stages in the field. We found that one pair of the 7Ns genome chromosomes carried new leaf rust resistance gene(s). Moreover, wheat line 2-1-6-3 had a superior numbers of florets and grains per spike, which were associated with the introgression of the paired P. huashanica chromosomes. These high levels of disease resistance and stable, excellent agronomic traits suggest that this line could be utilized as a novel donor in wheat breeding programs.

Integrated Single-Molecule Long-Read Sequencing and Illumina sequencing reveals the resistance mechanism in response to barley yellow dwarf virus-GAV in Psathyrostachys huashanica

“…This subsequently proved that a small terminal segment of the 3Ns genome carried new stripe rust resistance genes that showed high levels of disease resistance [15]. In the same way, wheat x P. huashanica Keng 2Ns, 4Ns, 6Ns and 7Ns disomic addition lines were generated and showed enhanced tiller numbers and disease resistance [16][17][18][19]. In addition, a recent study showed that P. huashanica exhibited high resistance to barley yellow dwarf virus-GAV (BYDV-GAV) and disrupted the movement of the viral particles from inoculated leaves to new leaves [11].…”

Molecular cytogenetic characterization of a novel wheat–Psathyrostachys huashanica Keng T3DS-5NsL•5NsS and T5DL-3DS•3DL dual translocation line with powdery mildew resistance

“…In addition, 2Ns, 3Ns, 4Ns, and 5Ns disomic addition lines and a 2Ns(2D) substitution line are resistant to stripe rust [13][14][15][16]18]. A 6Ns disomic addition line and a small segment translocation line possess twin spikelets and more kernels per spike than its wheat parent [13,21], and a 7Ns disomic addition line showed high resistance to leaf rust [12]. However, only a few wheat-P. huashanica translocation lines are available for breeding despite its importance.…”

“…The colchicine treated H811 was crossed and backcrossed to 7182 to get heptaploid hybrid H8911 (2n = 49, AABBDDNs). Subsequently, H8911 was then backcrossed to 7182 or crossed to several other wheat cultivars, and generated a series of wheat-P. huashanica derived lines including wheat-P. huashanica 1Ns-7Ns disomic addition lines [12][13][14][15][16][17], 2Ns(2D) disomic substitution line [18], 5Ns(5D) disomic substitution line [19], and translocation lines [20,21]. These wheat-P. huashanica derived lines have more desired agronomic traits than their wheat parents, demonstrating that P. huashanica is a useful wild relative for wheat improvement.…”

Characterization of the Wheat-Psathyrostachys huashania Keng 2Ns/2D Substitution Line H139: A Novel Germplasm With Enhanced Resistance to Wheat Take-All

“…In the derived offspring, disease resistance of the addition line H1 was similar to that of P. huashania, six addition lines and three substitution lines displayed a moderate level of disease resistance, and the remaining lines were susceptible. More recently, synthetic approaches including cytological observations, GISH, EST-STS marker analyses, morphological analysis, and agronomic trait evaluation have led to the successful identification of a series of wheat-P. huashania disomic addition lines, including 1Ns (Du et al, 2014d), 2Ns (Du et al, 2014c), 3Ns (Du et al, 2014b), 4Ns (Du et al, 2014a), 5Ns (Du et al, 2013a), 6Ns (Du et al, 2013b), and 7Ns (Du et al, 2013c), and one disomic substitution line, namely 16-6 (Du et al, 2015). However, the use of wheat-P. huashanica-derived offspring for enhanced resistance against wheat take-all disease remains underexplored.…”