Dicamba and growth condition effects on doubled haploid production in durum wheat crossed with maize

Abstract

Doubled haploid plants are useful in genetic studies and plant breeding, but a consistent and satisfactory frequency of production has been difficult to achieve in durum wheat. Triticum turgidum L., using the maize pollen method. The objective of this study was to develop an objective method of producing doubled haploids in durum wheat. Plant growing and handling conditions, aspects of hormone treatments, wheat genotype and pollen source were considered. The number of caryopses, embryos, haploids, doubled plants and doubled plants that set seed were measured. Although growth conditions, pollen source, method of handling plants and wheat genotype are important considerations, the type of hormone was found to be most significant in the production of doubled haploid plants. When 50mg/l dicamba was substituted for 100 mg/l 2,4‐D the number of doubled haploids per spike increased from 0.2 for the best 2,4‐D treatment to 1.3 for the dicamba treatment. This increased frequency was largely attributed to an increase in the number of caryopses generated for each spike emasculated and from an increased frequency of germination of embryos to haploid plantlets. The best production of caryopses was 0.41 caryopses per florest with 2,4‐D. The best production of haploids per 100 florets was 12 with dicamba and 1.65 with 2,4‐D. The frequency of one doubled haploid per emasculated spike through the use of dicamba is a practical level for generating populations for genetic studies.

Common bunt resistance gene Bt10 located on wheat chromosome 6D

“…Sixty-two doubled haploid lines were developed from the F 1 progeny of the cross between bunt susceptible wheat cultivar Glenlea and AC Taber at the Semi-arid Prairie Agricultural Research Centre (Swift Current, SK) in 1993. The method was the same as that described by Knox et al (2000) in which 1 and 5 d after pollination with freshly harvested maize (Zea mays L.) pollen, the wheat spikes were sprayed with 100 mg L -1 of 2,4-D. Plants were grown in a growth cabinet with a 16 h light (approximately 250 µmol m -2 s -1 ) and 8 h dark photoperiod at 15°C.…”

Maximizing the identification of QTL for pre-harvest sprouting resistance using seed dormancy measures in a white-grained hexaploid wheat population

“…A population of 91 DH lines were developed from the F 1 plants using the maize pollination technique of Knox et al (2000). The female parent, SC8021-V2 (PI-554142), developed as a pre-harvest sprouting resistance line, has the pedigree Kenya-321/Peck.…”

New breeding tools impact Canadian commercial farmer fields

“…Since 1997, twenty five DH cultivars have been released in seven market classes (Table 2). In Canada, the predominant method to generate doubled haploids has been maize pollination of wheat ovules to generate haploid embryos followed by chromosome doubling (Aung et al 1995;Knox et al 2000). Only two DH cultivars were produced by another culture technique.…”

“…DT801 expressed lower fusarium head blight symptoms and lower deoxynivalenol mycotoxin than the checks. Durum wheat is more recalcitrant than hexaploid wheat to generate doubled haploids, which has been partially overcome by better protocols (Knox et al 2000).…”