Improvement in yield attributes and fatty acids composition in the derivative hybrids compared to their respective parents in Indian mustard (Brassica juncea L.)

Abstract

Erucic acid, more than 2 %, in mustard seed oil is considered unhealthy as edible oil, and also anti-nutritional for human consumption. The existing mustard varieties of Bangladesh contain 40-48 % erucic acid, which is a big concern for the country's nutritional, and food security and safety. Hence, to improve the seed oil quality of the existing variety, six popular cultivars of Brassica juncea mustard were crossed with a canola-grade line in 7 × 7 half diallel fashion, and the developed 21 F₁ hybrids were assessed for yield contributing traits, and fatty acids composition. Variables with significant variations were found, while days to siliquae maturity, plant height, days to first flowering, and seeds per siliquae have moderate narrow sense heritability. The estimated gene action indicated that dominant or over-dominant gene action was more prominent in governing the traits. The parents, P₁, P₃, and P₄ were discovered the best general combiners for early maturity and short phenology, whereas P₂ and P₇ were found to be the best general combiners for yield-attributing traits. Moreover, the hybrids P₁ × P₄, P₁ × P_6, P₂ × P₇, P₄ × P₆ and P₃ × P₅ were chosen as the promising hybrids due to their best specific combining ability, and desired heterotic effects on yield contributing traits. In addition, a significant decrease, on average 30-40 %, in erucic acid, but an approximately 20-25 % increase of oleic acid was found among the hybrids, in which the hybrids P₁ × P₆-S1, P₅ × P₆-S2 and P₅ × P₆-S4 demonstrated a better stability index. Overall, the obtained findings suggested that the hybrids, viz. P₁ × P₅, P₁ × P₆, P₂ × P₃, P₂ × P₇, P₄ × P₆, P₅ × P₆, and P₆ × P₇ were promising based on their early maturity, high-yielding, reduced erucic acid, and high oleic acid contents.

Keywords: Combining ability; Diallel mating; Fatty acids profile; Gene action; Heterosis.

Fig. 1

Correlation coefficient analysis among yield and yield contributing traits. Note: Note: DFF = Days to first flowering, D50%F = Days to 50 % flowering, DPM = Days to 80 % maturity, PH= Plant height (cm), NPB=Number of primary branches per plant, NSB=Number of secondary branches per plant, SL=Siliquae length (cm), SPP=Siliquae per plant, SPS=Seeds per siliquae, TSW = 1000 seed weight (g), YPP=Yield per plant (g) and HI=Harvest index (%).

Fig. 2

Morphological variations in yield attributes and seed coat color of 21 F₁ hybrids and 7 parents (P1–P7) of Brassica juncea. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

Fig. 3

Mean performance of the important four yield contributing traits of 21 F₁ hybrids and their 7 parents, a. days to maturity (DAS); b. plant height (cm); c. yield per plant (g) and d. harvest index (%).

Fig. 4

Phylogeny tree showing the positions of the 21 F₁ hybrids and their 7 parents into four different clusters based on the mean performance of twelve yield contributing traits.

Fig. 5

The general combining ability (GCA) effects of twelve traits of the seven parents. The upper panel (a) indicates the general combining ability (GCA) effects of DFF = Days to first flowering, D50%F = Days to 50 % flowering, DPM = Days to maturity, NPB=Number of primary branches per plant, NSB=Number of secondary branches per plant and PH= Plant height (cm), and lower panel (b) illustrates the GCA effects of SL=Siliquae length (cm), SPP=Siliquae per plant, SPS=Seeds per siliquae, TSW = 1000 seed weight (g), YPP=Yield per plant (g) and HI=Harvest index (%) of the seven parents. * & ** indicate 1 % and 5 % levels of significance, respectively.

Fig. 6

The specific combining ability (SCA) effects of twelve traits of 21 hybrids. The upper panel (a) indicates the specific combining ability (SCA) effects of DFF = Days to first flowering, D50%F = Days to 50 % flowering, DPM = Days to maturity, NPB=Number of primary branches per plant, NSB=Number of secondary branches per plant and PH= Plant height (cm) and lower panel (b) illustrates the SCA effects of SL=Siliquae length (cm), SPP=Siliquae per plant, SPS=Seeds per siliquae, TSW = 1000 seed weight (g), YPP=Yield per plant (g) and HI=Harvest index (%) of the 21 F₁ hybrids. * & ** indicate 1 % and 5 % levels of significance, respectively.

Fig. 7

Effects of heterosis over better parent (Heterobeltiosis) and over check variety (Standard heterosis) of hybrids for the twelve variables. The upper panel (a) manifests the heterosis over better parent (Heterobeltiosis) and over check variety (Standard heterosis) of DFF = Days to first flowering, D50%F = Days to 50 % flowering, DPM = Days to maturity, NPB=Number of primary branches per plant, NSB=Number of secondary branches per plant and PH= Plant height (cm) and lower panel (b) showed the heterobeltiosis and standard heterosis of SL=Siliquae length (cm), SPP=Siliquae per plant, SPS=Seeds per siliquae, TSW = 1000 seed weight (g), YPP=Yield per plant (g) and HI=Harvest index (%) of the 21 F₁ hybrids. * & ** indicate 1 % and 5 % levels of significance, respectively.

Fig. 8

Percentage of total saturated fatty acids (TSFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) among the selected hybrids and parental lines.

Fig. 9

Erucic acid concentration (%) in the seed oil among the selected hybrids and parental lines.

Fig. 10

The proportional ratio of oleic to linoleic acid and linoleic to linolenic acid among the selected hybrids and parental lines.