Characterization of wheat – Psathyrostachys huashanica small segment translocation line with enhanced kernels per spike and stripe rust resistance

Abstract

Psathyrostachys huashanica Keng (2n = 2x = 14, NsNs), a distant wild relative of common wheat, possesses rich potentially valuable traits, such as disease resistance and more spikelets and kernels per spike, that could be useful for wheat genetic improvement. Development of wheat - P. huashanica translocation lines will facilitate its practical utilization in wheat breeding. In the present study, a wheat - P. huashanica small segmental translocation line, K-13-835-3, was isolated and characterized from the BC1F5 population of a cross between wheat - P. huashanica amphiploid PHW-SA and wheat cultivar CN16. Cytological studies showed that the mean chromosome configuration of K-13-835-3 at meiosis was 2n = 42 = 0.10 I + 19.43 II (ring) + 1.52 II (rod). GISH analyses indicated that chromosome composition of K-13-835-3 included 40 wheat chromosomes and a pair of wheat - P. huashanica translocation chromosomes. FISH results demonstrated that the small segment from an unidentified P. huashanica chromosome was translocated into wheat chromosome arm 5DS, proximal to the centromere region of 5DS. Compared with the cultivar wheat parent CN16, K-13-835-3 was highly resistant to stripe rust pathogens prevalent in China. Furthermore, spikelets and kernels per spike in K-13-835-3 were significantly higher than those of CN16 in two growing seasons. These results suggest that the desirable genes from P. huashanica were successfully transferred into CN16 background. This translocation line could be used as novel germplasm for high-yield and, eventually, resistant cultivar breeding.

A 1Ns Disomic Addition from Psathyrostachys Huashanica Keng Confers Resistance to Powdery Mildew in Wheat

“…Crosses between wheat and P. huashanica are relatively recent, and P. huashanica is significant among numerous species related to wheat because of its excellent agronomic characteristics. Several wheat-P. huashanica progeny lines were generated in previous studies, including disomic addition lines [33], disomic substitution lines [34], and small fragment translocation lines [17]. In our laboratory, 35 derived lines were developed by crossing common wheat 7182 with P. huashanica via embryo rescue culture and backcrossing, and these intermediate materials with different agronomic traits provide a suitable foundation for exploiting genes from P. huashanica.…”

“…A series of wheat-P. huashanica addition lines and substitution lines were then produced, as well as a new intergeneric amphiploid PHw-SA by treating the F 1 hybrid from a cross between wheat cv Kaixianluohanmai and P. huashanica with colchicine [15,16]. Based on these studies, a small fragment wheat-P. huashanica translocation line K-13-835-3 was developed from a BC 1 F 5 population of a cross between PHw-SA and wheat cv CN16, with attractive agronomic traits and high resistance to stripe rust was selected [17]. Zhang et al [18] conducted random amplified polymorphic DNA (RAPD) analysis using the genomic DNA from P. huashanica and common wheat, and characterized two novel sequence characterized amplified region (SCAR) markers called Psh-D15 270 and Psh-F19 558 , that were present only in the Ns genome.The use of resistance to powdery mildew found in P. huashanica to produce resistant wheat cultivars was mentioned rarely in previous studies.…”

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.…”

“…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. However, all the known wheat-P. huashanica translocation lines are poorly characterized [20][21][22][23].…”