Potential of the C Genome of Different Variants of Brassica oleracea for the Improvement of Agronomic and Seed Quality Traits of B. napus Canola

Abstract

The narrow genetic base of Brassica napus L. canola, especially of its C genome, is an impediment for continued improvement of this crop. We investigated the gene pools of different variants of B. oleracea L. to improve agronomic and seed quality traits of B. napus canola. For this, B. napus canola inbred populations were developed from six interspecific crosses, involving a single B. napus canola line and six accessions of B. oleracea belonging to four variants of this species, following two breeding techniques (F2– and BC1–derived lines). Among these, the population derived from crossing with var. italica gave the greatest seed yield and also had shorter duration of flowering than most of the other populations. The population developed using var. botrytis had the highest seed oil content, and seed yield was comparable with the population developed using var. italica. Populations based on var. capitata had the lowest oil but greater protein content than most of the populations. Several lines from these interspecific crosses exceeded seed yield of the B. napus parent and also had acceptable agronomic and seed quality traits. Comparing the two breeding techniques, the F2–derived population gave greater yield than the BC1–derived population, whereas the BC1–derived population flowered and matured earlier than the F2–derived population. Genetic distance of the inbred lines from the B. napus parent showed positive correlation of r ≥ 0.4 with days to flowering and seed protein content and negative correlation with seed oil content, whereas correlation with seed yield was negative and weak (r = −0.18). Thus, the results showed that the B. oleracea gene pool, especially var. italica and botrytis, can be used to improve spring B. napus canola, as well as to broaden the genetic base of this crop.

Potential of the C Genome of the Different Variants of Brassica oleracea for Heterosis in Spring B. napus Canola

“…Of the six population studied, the inbred population derived from the cross involving broccoli gave higher yield than the inbred populations derived from the other five crosses. While evaluating only the inbred lines in larger plot (5.0 m × 1.7-1.8 m) trials, we also found similar results (Nikzad et al, 2019). However, in this study, we found that the test hybrids of the inbred population of broccoli yielded less than the other test hybrid populations; this inbred population, in fact, had the least genetic distance from the B. napus parent (data not shown).…”

“…Genomic DNA of the above-mentioned 227 (110 + 117) F 2 -and BC 1 -derived inbred lines and their seven parents (B. napus A04-73NA and six B. oleracea cultivars/lines) was extracted using SIGMA DNA extraction kit (Sigma-Aldrich, St. Louis, MO, USA) following manufacture's instruction. A total of 95 polymorphic SSR markers (Nikzad et al, 2019) from nine Cgenome linkage groups (LG) were selected from 418 markers for genotyping the populations. Polymerase chain reactions (PCR) for amplification of the genomic DNA was performed in a total volume of 15.5 μl, which included 20 ng genomic DNA, 5× PCR reaction buffer, 25 mM MgCl 2 , 0.6 unit Taq DNA polymerase (Promega Corporation, Madison, WI), 10 mM each dNTP (Invitrogene Life Technologies Inc., Burlington, ON), 5 μM of each forward and reverse primer, and 5 μM tag F (fluorescent dyes FAM, VIC, NED, and PET).…”

Identification of QTL and alleles for agronomic and seed quality traits in C genome using a Brassica napus population diversified with B. oleracea

“…A total of 184 B. napus inbred lines, which included 90 F 10 and 94 BC 1 F 9 lines, developed from F 2 and BC 1 (F 1 × B. napus parent) of six B. napus × B. oleracea interspecific crosses involving the single B. napus line and the six B. oleracea lines and cultivars were used in this study. The detail of the development of these B. napus inbred lines and confirmation of their euploid (2 n = 38) nature was described previously (Iftikhar et al., 2018; Nikzad et al., 2019). In brief, the F 1 plants of the six interspecific crosses were self‐pollinated for F 2 seeds and were also backcrossed to the B. napus parent for BC 1 seeds.…”

“…We developed an inbred B. napus population from six interspecific crosses of B. napus × B. oleracea (AACC × CC = F 1 ACC) involving different varieties of B. oleracea to broaden the genetic base of the C genome of B. napus canola (Iftikhar et al., 2018; Nikzad et al., 2019). Given that wide diversity exists in B. oleracea (e.g., Izzah et al., 2013; Thakur et al., 2018), this population was expected to be highly diverse for the C genome and carry alleles which are not present in natural B. napus .…”

A Probe Into the Teaching Process of Engineering Courses in Colleges and Universities

“…Specifically, in the process of teaching [6][7][8] . we should pay attention to the introduction of the overall framework of the discipline to help students learn and transfer; guide students to explore the scientific theory and practical knowledge of the subject; select key contents and elaborate on key contents; arrange homework after class to improve the ability of analysis and calculation; and finally, carry out practice to improve perceptual knowledge [9][10][11] .…”