Plant lines

Brassica juncea and Brassica nigra lines

For the TuMV resistance tests, 34 lines of B. juncea and 27 lines of B. nigra were collected and evaluated for their resistance to TuMV isolate UK 1. The seeds of these lines were obtained from Warwick Crop Centre Genetic Resources Unit (GRU), IPK Gatersleben Germany, Institute of Vegetable and Flowers (IVF) Beijing, Saskatoon Research and Development Centre Canada and commercial outlets, covering various genetic and geographic origins (Table 2.1).

Table 2.1 − Information of plant materials in TuMV resistance tests.

Plant line

Species Geographical origin

Type Source

TWBJ01 B. juncea Malaysia Leaf Warwick GRU TWBJ02 B. juncea Bhutan Oilseed Warwick GRU TWBJ03 B. juncea Bhutan Oilseed Warwick GRU TWBJ04 B. juncea Bhutan Oilseed Warwick GRU TWBJ05 B. juncea Zimbabwe N/A Warwick GRU TWBJ06 B. juncea Zimbabwe N/A Warwick GRU TWBJ07 B. juncea Zimbabwe N/A Warwick GRU TWBJ08 B. juncea Zimbabwe N/A Warwick GRU TWBJ09 B. juncea Zimbabwe N/A Warwick GRU TWBJ10 B. juncea Zimbabwe N/A Warwick GRU TWBJ11 B. juncea Zimbabwe N/A Warwick GRU TWBJ12 B. juncea Zimbabwe N/A Warwick GRU TWBJ13 B. juncea Zimbabwe N/A Warwick GRU TWBJ14 B. juncea China Root IVF Beijing, China TWBJ15 B. juncea China Leaf IVF Beijing, China TWBJ16 B. juncea China Leaf IVF Beijing, China TWBJ17 B. juncea China Stem IVF Beijing, China TWBJ18 B. juncea China Stem IVF Beijing, China TWBJ19 B. juncea China Leaf Shandong, China TWBJ20 B. juncea China Root Shandong, China TWBJ21 B. juncea Bhutan Oilseed Warwick GRU TWBJ22 B. juncea Hong Kong Leaf Warwick GRU TWBJ23 B. juncea China Root Warwick GRU TWBJ24 B. juncea Uruguay N/A Warwick GRU TWBJ25 B. juncea Japan Leaf Warwick GRU TWBJ26 B. juncea Japan Leaf Warwick GRU

TWBJ28 B. juncea SUN N/A Warwick GRU

TWBJ29 B. juncea China Leaf Warwick GRU TWBJ30 B. juncea Japan Oilseed Warwick GRU TWBJ31 B. juncea India Oilseed Warwick GRU

TWBJ32 B. juncea India Oilseed Warwick GRU TWBJ33 B. juncea U.K. Leaf Warwick GRU TWBJ34 B. juncea India Oilseed Warwick GRU 060DH17 B. juncea N/A N/A Saskatoon,Canada TWBN01 B. nigra Germany N/A IPK

TWBN02 B. nigra Poland N/A IPK

TWBN03 B. nigra Greece N/A IPK

TWBN04 B. nigra Italy N/A IPK

TWBN05 B. nigra France N/A IPK

TWBN06 B. nigra Germany N/A IPK TWBN07 B. nigra Hungary N/A IPK TWBN08 B. nigra Pakistan N/A IPK

TWBN09 B. nigra Russia N/A IPK

TWBN10 B. nigra Greece N/A IPK

TWBN11 B. nigra Greece N/A IPK

TWBN12 B. nigra Greece N/A IPK

TWBN13 B. nigra Italy N/A IPK

TWBN14 B. nigra Italy N/A IPK

TWBN15 B. nigra France N/A IPK

TWBN16 B. nigra Alaska N/A IPK

TWBN17 B. nigra Turkey N/A IPK

TWBN18 B. nigra India N/A IPK

TWBN19 B. nigra India N/A IPK

TWBN20 B. nigra Yugoslavia N/A IPK

TWBN21 B. nigra India N/A IPK

TWBN22 B. nigra Denmark N/A IPK

TWBN23 B. nigra India N/A IPK

TWBN24 B. nigra Czechoslovaki a

N/A IPK

TWBN25 B. nigra N/A N/A KEW Gardens

Ni-100 B. nigra N/A N/A Saskatoon, Canada al-1-3 B. nigra N/A N/A Saskatoon, Canada

B. rapa and B. napus lines

Resistant and susceptible lines of “Tropical Delight” were used for the experiments on TuRB01b identification and introgression. “Tropical Delight” (T. Sakata and Company) is an F1 hybrid commercial Chinese cabbage (B. rapa) line, which has

extreme resistance to TuMV isolate UK 1 (Lydiate et al., 2014). Tropical Delight was self-pollinated and progeny were inoculated and tested to confirm their homozygosity for resistance or susceptibility. B. napus lines R4, S6 (Jenner and Walsh, 1996), 22S (Hughes et al., 2003), DH12075, NO1D, NO2D and PSA12, together with B. napus cultivars Global DH, Yudal, Darmor, Karoo and Cabriolet were used for research aimed at the identification of TuRB01. TuMV-resistant B. napus line Westar (Walsh et al., 1999) was used for introgression of TuRB01 into B. juncea.

2.1.2 Development of mapping populations for TuMV resistance gene(s) in B. juncea

Selfs and crosses of B. juncea

Because B. juncea is a self-compatible plant species, it is fairly straightforward to self. Successful self-pollination was accomplished by enclosing the racemes of a plant within a perforated transparent bread bag before flowering (Fig. 2.1). While making crosses and backcrosses, bud inoculation was conducted. Immature flower buds of appropriate size were emasculated by removal of anthers. The stigmas of these buds were then pollinated with pollen of the desired male parent. The racemes were labelled and enclosed within perforated transparent bread bags to prevent cross-contamination (Fig. 2.1). In some cases, pollinations were repeated.

Figure 2.1 – Self-pollinations and cross-pollinations of Brassica juncea in the glasshouse.

Resistant B. juncea lines and corresponding mapping populations

Reciprocal crosses were made between resistant individuals from four B. juncea

lines (TWBJ03, TWBJ14, TWBJ20 and TWBJ23) and a well-characterised UK 1- susceptible B. juncea line (060DH17) for which there is genomic information. Four F1 seed lines were produced and confirmed to be UK 1-susceptible. Four F1 seed

lines were selfed and backcrossed to S1 seed lines of resistant parent to produce F2

and BC1 populations, respectively (Fig. 2.2).

Figure 2.2 − Crossing strategy used to develop Brassica juncea BC1 populations segregating for resistance to TuMV.