Development Of Germplasm For High Essential Fatty Acids In Brassica Napus
Canola breeding and Breeding for high essential fatty acids, is necessary to improve the quality of brassica oils along with high yield, the present study will address this issue. Experiment will be conducted in the field of University of Agriculture Faisalabad, Fields of Plant Breeding and Genetics. Total 9 lines that will be crossed in Line × Tester pattern in which 6 lines (ZN-Z-R-10, G-96, Chakwal Sarsoon, Rainbow, Punjab Sarsoon and ZM-R-7) and 3 testers (DGL, Sharali and ZM-M-5) will be used. Breeding material will be developed through crossing in one season and in next season will be grown in field in randomized complete block design, three seeds of each entry per replication per treatment will be sown and will record the data at different stages first at seedling stage, flowering stage and at maturity stage. Data will be recorded for morphological traits, phonological traits and chemical traits. Recorded data will be analyzed by using analysis of variance, mean test and Line Tester analysis.
Pakistan is an agro-based country therefore its economy largely depends on agriculture. For this important field crops are improved in both terms yield and quality i.e. Wheat, rice and cotton but marginal crops such as oil seed crops also have potential to be the part of these field crops. Brassica is the 2nd largest group of oil seed crops after soybean but its oil quality is not so much superior and fatty acid profile is also needed to be improved. Pakistan is one of the largest edible oil importers in the world and MY 2017/18 imports are forecast at record 3.6 million metric tons. Oil consumption was 5000,000 metric tons in 2017.
To decrease the oil import, production of domestic oil must be increased and oil quality must also be improved. Brassica contains 36-50% oil and 33-48% proteins used in oil and meal industry. Oil is mainly used for cooking purposes and protein for meal of animals. Oil quality is generally defined in terms of both nutritional and functional aspects and incase of brassica in terms of fatty acid profile. Canola oil of Brassica napus has 60 % oleic acid, 20 % linoleic acid and 10 % linolinic acid that is moderate level of essential fatty acids and this oil is good enough for cooking purposes. Reduction of glucosinolates in brassica oil also makes it fit for meal purposes in animal husbandry. Oil quality improvement includes increment in concentrations of essential fatty acids along with reduction in glucosinolates contents. Canola oil contains less than 2 % Erucic acid and less than 30µmol glucosinolates. High contents of Erucic acid along with glucosinolates has bad effects on human health. High concentration of Erucic acid causes thyroid gland problems that leads to goiter and high concentration of linolinic acid helps in oxidation inside the cell therefore it is unhealthy for consumption therefore it should be reduced in brassica that is actually called fatty acid profiling. Brassica napus is ranked 3rd in oil seed crops and familiar crop among farmers. It is reported that 14.06 % oil contribution from brassica napus. Therefore it is needed to increase brassica yield as well as improve its oil quality.
Crop improvement programme will be fruitful if including accessions or lines contain genetic variability. Genetic variability is always crucial for a breeding programme. Conventionally it is established through crossing between two distant parents that is actually hybridization. Evaluation of accessions by using breeding approaches provide information regarding gene action. Gene action helps breeder for selection of suitable parents and then finally selection of suitable breeding method for crop improvement. There are many breeding approaches i.e. Diallel analysis, Line Tester analysis and Generation mean analysis. Combining ability analysis will provide information regarding desirable parents, magnitude and nature of gene action that is basic point for breeder. GCA SCA effects and then desirable parents can be selected. By using GCA SCA gene action can be suggested as dominance, additive or epistatic effect.
Koprna et al. (2006) conducted an experiment of 262 samples of Brassica napus L. From F2 segregating population by using NIR analysis (near infrared spectroscopy) and GC analysis (Gas Chromatography) for fatty acid profiling. Calibration equations were developed for 6500 NIRs and reference method GC was used to calculate Oleic acid (C18:1), linoleic acid (C18:2) and linolenic acid (C18:3). 50 random samples proved a high correlation coefficient (r). Fatty acid profiling was done.
Han-zhong et al. (2009) evaluated the heterosis for oil contents in Brassica napus L. He screened the lines and crosses having high oil contents. Out of 62 crosses, 30 showed significant mid-parent heterosis and seven showed significant heterosis over better parent for seed oil contents.
Hossam El-Din Saad El-Beltagi and Amal Amin Mohamed (2010) investigated five cultivars of rapeseed (pactol, silvo, topas, serw 4 and serw 6). These cultivars were evaluated for nutritional aspects like fatty acid composition, glucosinolate contents, tochopherols, amino acids and phenolics. All cultivars showed high genetic variation for fatty acids i.e. oleic acid ranges 10.52-13.74%, α-linolenic acid 8.83-10.32% and Erucic acid 0.15-0.91%. Variation for glucosinolates were small exceptionally silvo showed highest contents (5.97 μmol/g DW). Genetic variations for amino acids, tochopherols and phenolics were also observed.Turi et al. (2010) conducted an experiment in Brassica juncea for quality parameters and combining ability effects were calculated. General combining ability (GCA) effects were highly significant for oil contents and glucosinolate contents. General combining ability (GCA) effects were highly significant than specific combing ability (SCA) effects for certain traits i.e. glucosinolate, Erucic acid and protein contents. The parent genotypes NUM009, NUM123, NUM105 and NUM117 and their hybrids NUM009x NUM123, NUM103x NUM105, NUM113xNUM124 and NUM103x NUM120 had high GCA and SCA effects, respectively and therefore these could be exploited for further selection of high yielding progenies.
Omidi et al. (2010) performed a split-plot experiment for agronomic practices in canola genotype Hyola 401 and PF. He studied its effect on fatty acid composition. Agronomic practices include tillage (zero tillage, minimum tillage and conventional tillage) and sowing dates (early sowing Sep and late sowing Oct). Highest oleic acid found in Hyola401 at zero tillage and in early sowing and lowest was in PF at conventional tillage and late sowing. Therefore it is recommended first combination was best.
Verma et al. (2011) conducted a line× tester analysis using twelve lines and three testers to evaluate yield components i.e. number of primary branches , number of secondary branches, days taken to 50% flowering ,length of raceme, seed yield, 1000-seed weight and oil contents. Form results it was indicated that non-additive gene action controls these yield components. Specific combining ability (SCA) variance was significant for seed yield per plant. HUJM-05-1 x Kranti and RGN-173 x NDR 8501 crosses were highly significant for heterosis.
Valiollah Rameeh (2012) conducted an experiment by using six lines and two testers of spring rapeseed (Brassica napus L.) through line Tester. General combing ability (GCA) effects and specific combining ability (SCA) effects were calculated for Plant height, seed yield and yield contributing traits. Gene action was observed, results showed non-additive gene action for pods per plant and seed yield. Seeds per pod showed high narrow sense heritability (non-Additive gene action). Many crosses showed negative SCA effects for plant height.
Muhammad Zahir Ahsan (2013) evaluated Brassica napus L. through line × tester analysis by using five lines and three testers for yield related traits. Heterosis was calculated over mid parent and better parent for Plant height, number of primary branches, number of secondary branches, 1000-seed weight and seed yield. General combing ability effects were more than specific combing ability effects that showed additive gene action primarily present in breeding material. Heterosis over better parent were significant for seed yield showed that these hybrid could be exploited in breeding programme as had high genetic potential.
Kang et al. (2013) evaluated the genotypes of Brassica napus (UAF-2, Golarchi, Star, Hybripol and BA-0714 lines and DGL, Ayub-2000 and Range testers) through line Tester for yield contributing traits and seed yield. F1 hybrids were analyzed for following traits: plant height, number of secondary branches, number of silique per plant, number of seeds per silique, number of days taken to maturity, 1000- seed weight, seed yield per plant, oil and protein contents. ANOVA results showed that lines were significant for all traits except 1000 grain weight and protein contents and testers were non-significant for seed yield per plant. Specific combing ability effects were higher than General combining ability effects for all traits. Contribution of lines was more than testers.
Sixteen genotypes (120-R, B9527-1, MANROO, COMET, S-9, KN (20-35), UAF-1, N-RG, 20E, HYBRIPOL, V-22, STAR, 5-F, GOLARCHI, CRS-5 and PO-9 were evaluated by Kang et al. (2014). Data of 55 F1 Hybrids were recorded for yield contributing traits. Data was analyzed through line× tester analysis and specific combining ability (SCA) and general combining ability (GCA) effects were calculated. Contributions of lines were more than testers. Seven hybrid genotypes [CRS-5 × 20E, CRS-5 ×KN (20-35), CRS-5 × B9527-1, S-9 × 5-F, MANROO × B9527-1, and STAR × 20E, V-22 × KN (20-35)] were highly significant for yield contributing traits.
Shehzad et al. (2015) estimated combining abilities including genotypes of three Brassica napus L. testers (Punjab sarson, Durre-NIFA and Legend) and five lines (Duncled, K-258, ZN-R-1, ZN-R-8, ZN-M-6) through line Tester design. Line ‘Duncled’ was proved good general combiner for oil (8.8), protein (3.7), Erucic acid (33.0), oleic acid (13.0) and glucosinolates (-19.3) over other lines and tester ‘Durree-NIFA’ for protein (6.6), Erucic acid (-23.4), and linolenic acid (-5.3) over other testers. Research showed that non-additive genetic effects for most of traits except oil. Sharafi et al. (2015) examined 20 accessions of brassica species for oil contents and fatty acid composition. Results of this study depicted that oil contents varied from species to species as Brassica napus 46%, Brassica nigra 21%, Brassica oleracea 28% and brassica compestris 31%. Quality controlling fatty acids like oleic acid, linoleic acid linolenic acid, Erucic acid, Palmitic and steric acid accounted 89-94%. Results showed that there is high genetic variation among species for oil contents and fatty acids therefore seed oil is fitted for human consumption as well as for industrial use.
Ahmad et al. (2015) evaluated 20 rapeseed (10 entries of Brassica napus and Brassica compestris each) for biochemical characterization. Major long chain fatty acids, proteins content, glucosinolates, moisture percentage and oil contents characters were studied. The biochemical assessment of Brassica napus and Brassica compestris showed the range of 49.0-53.8 % oleic acid, 7.9-9.6 % linolenic acid, 23.2-30.4 % protein contents, 6.5-7.8 % moisture and 43.3-47.4 % oil contents in Brassica napus while that of Brassica compestris contained 38.5-47.9 % oleic acid, 8.0-10.2 % linolenic acid, 22.8- 26.0 % protein contents, 5.5-7.6 % moisture and 44.1-48.1 % oil contents. Most of lines were high oil content, protein contents and fatty acid containing. Almost all the lines were high in Erucic acid and glucosinolates except Brassica compestris line 399596 which was low in glucosinolates (28.8 μmol g 1).Further, highly significant negative correlation was observed for protein and oil contents among all the genotypes studied. Ali et al. (2015) evaluated 56 F1 hybrids using Diallel design. 34 crosses among these F1 showed significant heterosis for oil contents (%). Regarding glucosinolate contents 16/56 depicted negative heterosis, 32/56 crosses showed negative heterosis for Erucic acid contents. For protein, oleic acid, linoleic acid and linolenic acid, 32/56.49/56,32/56 and 22/56 crosses showed significant results over heterosis either positive or negative significance. In other words high genetic variation was present in these hybrids for oil content as well as for fatty acids.
Valiollah Rameeh (2015) investigated the gene action in 20 F1 hybrids developed through line× tester (normally maturing five lines and early maturing four testers). General combining ability and specific combining ability was estimated. Analysis of variance showed genetic variation among parents and crosses. Hybrid performance was good than the parents. L41×Foma2, Zafar×R42 and L22B×R38 crosses were significant for specific combining ability (SCA) effects of seed yield. Narrow sense heritability for number of branches and pod length were high that signified the additive gene action. Naheed et al. (2017) evaluated F2 populations of 4×4 full Diallel crosses and parents in terms of combining ability for seed yield and yield related attributes. Analysis of variance showed that genotypes are significantly different for all yield contributing traits. Analysis of variance showed that yield per plant ranged 4.27-9.17g, pods per raceme 42-89 and per pod seeds ranged 8-18. GCA and SCA were significant for pods per raceme and per pod seeds and seed yield. SCA effects were more than GCA effects that signified that highly non-additive gene action present in germplasm for all yield contributing traits. Gyanendra Kumar Rai et al. (2018) conducted an experiment of 26 genotypes of Brassica species for evaluation of oil and fatty acid contents. Significant differences were found in genotypes for oil quality. Brassica napus contained 37.82–40.56% oil contents, saturated fatty acid (Palmitic acid) 3.70–5.15%,oleic acid 16.15–37.98%, linoleic acid 18.57- 26.93% and linolenic acid 9.99- 17.23%.Brassica juncea contained oil contents 32.67–39.47%,saturated fatty acid (Palmitic acid) 3.08–3.85%,oleic acid 0.80–48.70%, linoleic acid 11.00- 45.30 %and linolenic acid 11.10- 26.72%. Brassica rapa contained oil contents 32.67–39.47%, saturated fatty acid (Palmitic acid) 3.70–5.15%,oleic acid 6.21–16.15%, linoleic acid 14.08- 18.18% and linolenic acid 9.82- 26.66% .The minimum Erucic acid content was recorded in Brassica juncea genotypes PM-24 (0.80%) and significantly at par with PM- 21, PM-22, Pusa Karishma and Nov Gold, whereas maximum Erucic acid content were recorded in Pusa Bold (49.40%), DGS-1(34.96%) and RSPT-02 (49.99%) in Brassica juncea, Brassica napus and Brassica rapa, respectively. Brassica species were significantly varied for fatty acid contents.
