Int. J. Agron. Agri. R. International Journal of Agronomy and Agricultural Research (IJAAR) ISSN: 2223-7054 (Print) 2225-3610 (Online) http://www.innspub.net Vol. 10, No. 5, p. 9-16, 2017 OPEN ACCESS RESEARCH PAPER Combining ability and correlation studies in 6×6 diallel crosses of sunflower (Helianthus annuus L.) Amin Ullah Jan*1,2 , Raziuddin2, Midrarullah1, Shariat Ullah3, Ajmal Iqbal3, Ayaz Ahmad3, Siraj Ahmad4, Fazal Mabood3, Khaista Rahman3 1 Department of Biotechnology, Faculty of Science, Shaheed Benazir Bhutto University, Sheringal Dir Upper, KPK, Pakistan 2 Department of Plant Breeding and Genetics, Agricultural University Peshawar, KPK, Pakistan 3 Department of Botany, University of Malakand, Chakdara, Pakistan 4 Department of Botany, Govt. Post Graduate Jahanzeb College, Swat, Pakistan Article published on May 22, 2017 Key words: Combining ability, Correlation, GCA, SCA, Sunflower Abstract The current studies was carried out to determine combining ability and correlation in 6×6 diallel crosses of sunflower genotypes for some physiological traits at Khyber Pakhtunkhwa Agricultural University Peshawar during 2009-10.The planted materials consisted of parental lines and their F1 hybrids using randomized complete block design with three replications. Data were recorded on yield and other important agronomic characters. General combining ability (GCA) and specific combining ability (SCA) were significant for all parameters except, seeds head-1. GCA effects for head size, stem thickness were greater than SCA showing contribution of additive gene effects. For flowering and 100 grain weight SCA effects were of greater magnitude than GCA and showing contribution of non-additive gene effects. Plant height exhibited significant (P@ 0.01) positive correlation with flowering and 100 grain weight. Seed head -1 and head size exhibited significant positive correlation with 100 grains weight. Among parental genotypes Rising Sun, US-444 and HS-K6 were the best general combiners for all the traits. Cross combinations Rising Sun × HS-K6, Ausigold-7 × US-444, Ausigold-7 × SMH-0917, Hysun-33 × HS-K6, and Ausigold-7 × HS-K6 showed promising results for majority of the traits, hence could be used in future breeding programs. * Corresponding Jan et al. Author: Amin Ullah Jan  aminjan@sbbu.edu.pk Page 9 Int. J. Agron. Agri. R. Introduction Through the availability of this information, sunflower Edible oil is major constituent of our diet but Pakistan improvement program can be improved considerably. is chronically deficient in its production, and large The current research aims to produce such varieties quantity of the country’s edible oil requirements are and inbreed line of sunflower, having high yielding met through imports. Oilseed sector, due to ever potential. increasing consumption of edible oil, has attained critical importance in the economy of Pakistan. Total availability of edible oil during 2011-2012 was 1749 million tons, whereas local production stood at 0.680 million tons which accounted for 24% of the total availability while the remaining 1246 million tons was made available through imports (Economic Survey of Pakistan, 2011-2012). This gap in the consumption and production can be filled by introducing cultivars with high edible oil contents, lodging resistance, high seed yield, drought tolerance and early maturity. Domestic production of edible oil can be increased by increasing the area and per acre yield of conventional and non-conventional oilseed crops. The area under oilseed crops cannot be increased as land resources are limited therefore, the only way left is the improvement of gentic potential of existing oilseed crops and introduction of new crops. Sunflower (Helianthus annuus L. 2n = 34) belongs to the family Compositae. It is one of the three crop species along with soybean and rapeseed which account for approximately 78% of the world vegetable oil (Miller, Materials and methods This research work was carried out at Khyber Pakhtunkhwa Agricultural University, Peshawar during 2009-2010. Six different sunflower lines (Rising Sun, Ausigold-7, US-444, Hysun-33, SMH0917 and HS-K6) were planted in field with a row length of 2 m, with plant to plant distance of 12 cm and row-to-row distance of 0.75 m. During spring 2009, the parental lines were crossed in 6×6-diallel fashion. In spring 2010, all the F1 crosses (direct and reciprocal) along with parental lines were grown in RCB Design with three replications to record data on the different morphological and yield parameters. All the agronomic practices like thinning, hoeing, weeding, fertilizer application and irrigation were carried out whenever needed. The data were recorded on the following parameters. Plant height (cm): Plant height was measured in cm from the soil surface to the base of capitulum at physiological maturity. 1988). Sunflower appears to be the only crop which Days to flowering: For 50% flowering, data were can play a vital role in supplementing our local oil recorded in number of days taken from the sowing production due to its high yield potential, drought date resistance, salt tolerance and adjustment in the flowered. in each genotype at a stage when 50% plants present cropping pattern. Being a short duration crop, it can be grown successfully twice a year under Head size (cm²): Head size was measured from one irrigated as well as rain fed conditions (Pascale and edge of the head to the other. Damario, 1997). Sunflower seed contain essential amino acids and proteins. In addition, its oil contains high levels of unsaturated fatty acids (linoleic acid; 70% and oleic acids; 20%) and low levels of saturated fatty acids (palmitic acid and stearic acids) which make this oil as a premium commodity as cooking oil. It is also a good source of calcium, phosphorus, Stem thickness (cm): The stem thickness of randomly selected plants was measured at the middle of stem with the help of Vernearcaleper. Seeds head-1: Total number of seeds in each head was counted from the selected plants. nicotinic acid and vitamin E (Khalifa et al., 2000). 100-grain weight: Random sample of 100-grain was Combining ability is the ability of two parents to drawn from selected plants. These grains were sun transmit favorable or unfavorable traits to their dried for two days and weighed in grams by electrical progeny. balance. Jan et al. Page 10 Int. J. Agron. Agri. R. Seed yield plant-1: The total seeds harvested from a Where: plant were sun dried and weighted in grams. Sij = Specific combining ability between ith and jth lines. Statistical analysis: Data were subjected to analysis Yij = Mean value of the F1 resulting from crossing the of variance following the method of (Steel and ith and jth lines. Torrie,1980). Yji = Mean value for F1 resulting from crossing the jth and ith varieties Genetic variance = Vg = (M1 – M2)/ r Yi. = Total of mean values of F1’s resulting from crossing Environmental variance = Ve = M2 jth line with ith varieties. Heritability = h2BS Combining ability = Vg/ Vp Y.i = Reciprocal values of Yi. analysis:For traits showing significant differences, data were further subjected to Y.j = Total values for F1’s resulting from crossing the ith line with jth line. Combining Ability Analysis according to (Griffing, Yj. = Values of reciprocal F1’s of Y.j 1956)Method-I based on Eisenhart's Model-II given Y. = Grand total of the observations. in “Biometrical Methods in Quantitative Genetic Phenotypic correlation: The phenotypic correlation Analysis” by (Singh and Chaudhery) as under: (rp) between two traits, X1 and X2, were calculated in General combining ability (GCA) F1 generation using the formula described by (Kwon gi = and Torrie, 1964). 1 1 ( Y i . + Y . i) - 2 Y.. 2n n rp = COVP (X1, X2) √QVP (X1). VP (X2) Where: gi=General combining ability effects for line i. Where, n=Number of parents/varieties. CovP (X1, X2) = Phenotypic covariance for traits X1 Yi. = Total of mean values of F1’s resulting from crossing and X2 in F1 generation. jth lines with ith lines. VP (X1) & VP (X2) = Phenotypic variance for traits X1 Y.i = Total of mean values of F1’sresulting from crossing and X2 in F1 generation. ith lines with jth lines. Y. = Grand total of all the mean values in the table. Specific combining ability (SCA) Results and discussion Plant height Plant height is a function of both genetic constitution 1 1 1 ( Y i .+Y . i +Y j .+Y . j) + 2ofY..a plant and the environmental conditions under sij = ( Y ij +Y ji ) 2n 2 n which it is grown (Skoric, 1992). All sunflower genotypes showed significant differences regarding plant height (Table 1). Table 1. Mean squares for ANOVA and combining ability in 6x6 diallel crosses of sunflower. Parameters Replication Mean Squares (Df = 2) ANOVA Genotype Mean Squares (Df = 35) Error Mean Squares (Df = 70) General Combing Ability (Df = 5) Plant height 128.12 2071.04** 179.0 296.80** 1062.42** 59.67 Days to flowering 2 1.583 52.49** 8.28 15.76** 28.04** 2.76 Leaves per plant Head size(cm) Stem thickness Seeds per head 100-grain weight 8.065 4.194 4.33 8 60725.6 0.271 43.85** 36.92** 0.48** 87266.99* 2.03** 10.29 12.35 0.02 43066.1 0.44 20.60** 17.37** 0.29** 30180.57ns 0.27ns 10.78** 9.72** 0.14** 19614.81ns 0.88** 3.43 4.12 0.01 14355.35 0.14 Seed yield plant-1 116.766 499.327** 187.090 104.26ns 171.33** 62.36 8.569 21.02** 0.04 4.17** 5.77** 0.01 Oil % Combining ability Specific Combining Ability (Df =15) Error (D f=70) ** Highly significant at 0.01 level, * Significant at 0.05 level, DF = Degree of freedom. Jan et al. Page 11 Int. J. Agron. Agri. R. For plant height genotype, Rising Sun elucidated The highest negative desirable general combining highest positive general combining ability followed by ability for plant height was displayed by genotype US- genotype SMH-0917. 444 (Table 2). Table 2. General Combining Ability effects for various traits in a 6x6 diallel cross of sunflower. Parental Plant height Days Lines (cm) flowering Rising Sun 7.59 -0.03 US-444 -7.09 -0.42 -1.89 SMH-0917 HS-K6 3.09 -1.66 thickness Head size (cm) -1.25 Ausigold-7 Hysun-33 to Stem (cm) -0.24 1.06 Seed head-1 100 seed weight (g) 1.36 45.59 0.27 Seed yield -0.05 1.11 -11.46 0.19 -0.97 -81.35 -0.61 -0.05 0.08 22.31 -0.16 -0.53 0.11 0.19 -25.88 -0.08 -0.05 0.71 -0.09 -1.78 50.79 -0.02 -0.05 0.45 0.05 0.07 0.41 0.07 1.75 -0.07 Oil % plant-1 (g) -0.48 0.56 -0.44 -0.7 -0.43 The results are in agreement with the work of combining ability while the cross Rising Sun × HS-K6 (Abdullah et al., 2010, Hand et al., 2006, Jan et al., had lowest negative specific combining ability effect 2003) who found high negative GCA effect for plant for plant height (Table 3). These results are line in height. SCA effect showed significant differences for agreement with those of (Goksoy et al., 1999, Burli et plant height (Table 1). The cross combination al 2001; Jan et al., 2003) who reported significant Ausigold-7 × HS-K6 showed high negative specific negative SCA effect for plant height. Table 3. Specific Combining Ability effects for various for morpho-physiological traits in a 6x6 diallel crosses of sunflower. Specific Combining Ability Plant Height Days to Stem Head Seed 100 Seed (cm) Flowering Thickness Size Head-1 Weight (g) 1.16 -1.47 (cm) -0.15 (cm) -0.94 -33.4 -1.78 -2.50 -0.19 -0.19 -2.47 0.01 Rising Sun × Ausigold-7 Rising Sun × US-444 Rising Sun × Hysun-33 -27.47 Seed Yield Plant-1 (g) Oil% -0.04 -0.27 -1.79 -78.18 -0.28 0.20 -1.61 -1.42 20.49 -0.27 0.31 -1.92 Rising Sun × SMH-0917 -9.46 -2.39 0.35 3.31 -2.48 -0.03 -0.08 -0.71 Rising Sun × HS-K6 -1.54 0.67 -0.05 0.28 50.69 0.35 -0.16 1.15 Ausigold-7 × US-444 -4.83 0.03 -0.20 4.89 199.21 0.08 0.31 -0.81 -0.28 0.28 0.50 29.38 -0.59 -0.50 -1.17 -3.36 0.56 -1.11 -66.59 -0.63 0.16 -0.21 Ausigold-7 × Hysun-33 -12.19 Ausigold-7 × SMH-0917 2.16 Ausigold-7 × HS-K6 -29.59 0.19 -0.21 -1.14 -83.93 0.17 -0.15 0.07 US-444 × Hysun-33 -12.19 -0.28 0.28 0.50 29.38 -0.59 -0.50 -1.07 US-444 × SMH-0917 -10.12 -0.72 0.05 -1.86 25.46 -0.05 -0.65 0.13 US-444 × HS-K6 -14.36 -1.00 0.01 -0.72 -56.87 -0.35 0.18 -0.66 Hysun-33 x SMH-0917 -16.98 -0.19 -0.43 -1.25 29.96 -0.32 0.34 0.1 -3.64 0.19 1.06 -130.54 -0.12 0.31 -1.45 -0.72 -0.17 -2.39 -74.84 -0.98 -0.56 0.54 Hysun-33 × HS-K6 SMH-0917 × HS-K6 Jan et al. -2.06 1.29 Page 12 Int. J. Agron. Agri. R. Days to flowering significant negative GCA effects for days to flowering Early flowering is the indication for early maturity in sunflower which confirmed our results. SCA effect which results in timely vacation of land for second showed significant differences for flowering (Table 1). crops or other following crops like wheat, barley etc. All The highest negative SCA effect for days to flowering sunflower genotypes under study exhibited significant showed by Hysun-33 × HS-K6 and was a good difference regarding days to flowering (Table 1). The combiner for earliness (Table 3). These results are in highest negative GCA effect showed by genotype Rising line with the finding of (Kaya and Atakisi, 2004, Sun followed by genotype Hysun-33 (Table 2). Similar Radhika et al., 2001, Ashok et al., 2000) who found results have been reported by (Arshad et al., 2007, significant difference and negative SCA effects for Naik et al., 1999, Ashok et al., 2000) who observed early flowering in sunflower hybrids. Table 4. Correlation among various morpho-physiological traits in 6x6 diallel crosses of sunflower. Traits Plant Days to Stem Head Flowering Thickness Size 0.42** 0.02* 0.37* Seed Head-1 0.25ns 100 Seeds Seed Yield Weight Plant-1 0.53** 0.44** Height Days to Oil % 0.30ns -0.08ns -0.03ns 0.02ns 0.30ns 0.2 1ns 0.21ns -0.09ns -0.24ns -0.13ns 0.19ns -0.13ns 0.28ns 0.43** 0.39* -0.19ns 0.50** 0.83** 0.15ns 0.85 * * 0.16ns Flowering Stem Thickness Head Size Seed Head-1 100 Seeds Weight Oil % 0.85** ** Correlation is significant at the 0.01 level, * Correlation is significant at the 0.05 level. Stem thickness Head size Stem thickness play a vital role to avoid the lodging, The size of head contributes substantially to final seed greater the stem thickness lesser chance of lodging. yield of sunflower as it influences both the number of Stem thickness for all parental genotypes and their F1 seed head-1 and seed yield. Head sizes for parental crosses were significantly different (Table 1). The maximum GCA effect for stem thickness, was demonstrated by genotype US-444 followed by genotype SMH-0917 (Table 2). Our results are in genotypes and F1 hybrids were significantly different (Table 1). Genotype Rising Sun showed maximum GCA effect for head size followed by genotype agreement with that of (Sassikumar and Gopalan, Ausigold-7 (Table 2). Abdullah et al., (2010), who 1999, Jan et al., 2003) who found maximum GCA observed significant GCA effects for head size which effect for stem thickness. SCA effect for stem thickness confirmed was significantly different in all hybrids (Table 1). The Ausigold-7 × US-444 showed the highest positive SCA cross combination Ausigold-7 × SMH-0917 showed effect while Ausigold-7 × Hysun-33 and US-444 × highest positive specific combining ability while the Hysun-33 showed the lowest positive SCA effect hybrid Rising Sun × Hysun-33 and US-444 × HS-K6 showed lowest positive specific combining ability (Table 3). Our findings are in agreement with those of (Jan et al., 2003, Radhika et al., 2001) who reported our results. The cross combination (Table 3). Goksoy et al., (1999) reported that nonadditive effect were predominant in the control of head size. high SCA effect for stem thickness. Jan et al. Page 13 Int. J. Agron. Agri. R. Seed head-1 Oil content (%) The number of seed head-1 is an important yield Sunflower oil is premium oil in the market because of component of sunflower that plays a remarkable role its high percentage of unsaturated fatty acids. The in genotype palmitic acid and stearic acid are the major saturated explicated non-significant GCA effect for seed head-1 fatty acid whereas oleic acid and linoleic acid are the determining the grain yield. All (Table 1). Genotype HS-K6 showed highest positive GCA effect followed by genotype Rising Sun (Table 2). Abdullah et al., (2010) and Hand et al., 2006 reported non-significant GCA effect for seeds head-1. Similarly SCA effect for seeds head-1 were observed nonsignificant. The maximum positive specific combining predominant unsaturated fatty acid. Higher oil content is the major objective of sunflower breeding programs around the globe. Mean values for oil content varied significantly for genotypes. Genotype SMH-0917 showed maximum GCA effect followed by ability effect was displayed by Ausigold-7 × US-444 genotype HS-K6. Hand et al., (2006), Jan et al., (Table 3). Sassikumar and Gopalan (1999) found non- (2003) also reported that additive effect were significant SCA differences for seeds predominant in the control of oil content. Our results head-1. are in agreement with the findings of Jan et al., 100 seed weight (2003) and who observed significant variations in oil 100 seed weight is an important yield parameter in content of sunflower genotypes. The hybrids Rising determining the yield potential of a crop as it expresses the magnitude of grain development. The data regarding 100 seed weight of sunflower showed non-significant differences (Table 1). Genotype Rising Sun showed maximum GCA effect followed by Sun × HS-K6 showed the highest positive SCA effect for oil content. These results are in line with the findings of (Jan et al., 2005) who found significant SCA differences for oil content. genotype US-444 (Table 2). Our results are in agreement with that (Kumar et al., 1999, Hand et al., Correlation 2006) who reported non-significant GCA effects for Correlations have to be made in the light of genetic 100 grain weight. There were significant SCA behavior, genotypic correlation values are used for differences in all genotype for 100-seed weight (Table further analysis. Genetic relation of traits may result 1). The cross combination Rising Sun × HS-K6 from pleotropic effects of a gene, linkage of two genes, exhibited the highest positive specific combining chromogema and regimental affiliation or due to the ability (Table 3). Our results confirm the studies of environmental influences (Sgro and Hoffmann 2004). (Goksoy et al., 1999, Kannababu and Karivaratharaju Plant height exhibited highly significant (P@ 0.01) 2000) who reported significant SCA effect for 100 positive correlation with leaves plant-1, flowering, 100 seed weight in sunflower hybrids. grain weight, while it was significantly (P@ 0.05) positive correlated with head size (Table 4). Our Yield plant-1 Yield is an ultimate objective of sunflower breeding results are similar with that (Ozer and Oral, 1999, and hybrid development programs. Yield plant-1 Ellahi, et al., 2009) who found significant correlation showed non-significant GCA differences for all for these traits. Days to 50 % flowering were Hysun-33 significant (P@ 0.05) positive correlated with 100 showed the highest GCA effect followed by Ausigold-7 grain weight (Table 4. These lines are in agreements (Table 2). These results are line in agreement with with the findings of (Khan et al., 2008) who found those of (Kumar et al., 1998). SCA effect for yield correlation for days to flowering. Head size showed plant-1 showed highly significant differences for all highly significant (P@ 0.01) positive correlation with genotype (Table 1). The cross combination Hysun-33 100 grain weight (Table 4). Our results are in genotypes (Table 1). In case of yield plant-1 × SMH-0917 showed the highest SCA effect while cross combination Ausigold-7 × SMH-0917 showed the lowest SCA effect (Table 3). Our findings are in agreement with those of (Goksoy et al., 1999, Kannababu and Karivaratharaju 2000). Jan et al. agreement with those of (Tahir et al., 2004, Machikowa and Saetang, 2008) who also reported that head size-1 strongly correlated with 100 grain weight. Page 14 Int. J. Agron. Agri. R. Seed head-1 exhibited highly significant (P@ 0.01) Dagustu N. 2002. Correlation and path coefficient positive correlation with 100 grains weight (Table 4). analysis of seed yield components in sunflower. Our results are in agreement with that (Tahir et al., Turkish Journal of Field Crops 7, 15-19. 2004) who reported correlation for seeds head-1 with Ellahi F, Hammad M, Tahir N, Sadaqat NA. 100 grain weight. 2009. Correlation and path co-efficient analysis for Conclusion achene yield and yield components in sunflower. Rising Sun was good combiner for plant height, 100- Pakistan journal of Agricultural Science 46, 20-24. garin weight and head size, US-444 was superior for stem thickness and HS-K6 surpassed for seed head-1. Goksoy AT, Turkec A, Turan ZM. 1999. A study Therefore, these genotypes could be used in future on the analysis of heterotic effect for certain breeding programs. Ausigold-7 × HS-K6 and Hysun- agronomical characters in cross populations of 33 × HS-K6 exhibited negative specific combining sunflower. Turkish Journal of Agricultural and ability effect for plant height and 50 % flowering, Forest, 23, 247-255. respectively. For stem thickness better combination expressed by Ausigold-7 × SMH-0917, for head size and seed head-1 Ausigold-7 × US-444 was a good specific combiner. For 100-grain weight rising sun × HS-K6 was the best combiner. Griffing G. 1956. Concept of GCA and SCA in relation to diallel system. Australian Journal of Biological Science 9, 463-493. Habib H, Mehdi SS, Anjum MA, Mohyuddin All these crosses were obtained by the combinations of high × low or low × high general combiners but high SCA effect was observed in the hybrid of these crosses. This might be due to the interaction of dominant alleles from good combiner and recessive alleles from poor combiner. ME, Zafar M. 2008. Correlation and path analysis for seed yield in Sunflower (Helianthus annuus L.) under charcoal rot stress conditions. International Journal of Agricultural Biology 2, 362-364. Hand N, Skoric D, Kraljevic M, Sakac Z, Jovanovic D. 2006. 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