Heterosis and Combining Ability for Yield and Other Agronomic Traits In

Open Agriculture. 2018; 3: 38–45

Research Article

Enzo Ferrari*, Aurora Picca, Rodolfo Domínguez and Héctor Paccapelo Heterosis and combining ability for yield and other agronomic traits in Triticale https://doi.org/10.1515/opag-2018-0005 1 Introduction received October 10, 2017; accepted January 24, 2018 Triticale (x Triticosecale Wittmak) appears to be an Abstract: The estimation of genetic parameters such as important crop if its use for human consumption were heterosis (Mh), heterobeltiosis (Hh), general combining expanded in the world (Pena 2004). Triticale shows ability (GCA) and specific combining ability (SCA) better adaptation than wheat to stressed environments, allows inferences about the predominant action of the particularly to water stress (Barary et al. 2002), and genes, indicates the appropriate selection strategy, and some cultivars have shown suitable characteristics facilitates identification of the best parents. The present for the production of flour for cookies (Oliete et al. study was carried out using a diallel cross system among 2010; Castaño et al. 2015a; Castaño et al. 2015b). five genotypes of Triticale (x Triticosecale Wittmak). The intensive efforts of genetic improvement in Triticale Genotypes CIMMYT 829 (G1), CIMMYT 830 (G2), CIMMYT have led to an improvement in grain yields at a similar 834 (G3), CIMMYT 820 (G4) and Antonio UNLPam (G5) rate to those of wheat in favorable environments and were crossed in a complete diallel combination without higher than wheat yields in marginal environments. reciprocal crosses, in La Pampa, Argentina. The additive Recent studies suggest the possibility of increasing the genetic effects were of greater importance than the non- yield through the production of hybrid varieties (Oettler et additive ones for the following traits: spike length (SL), al. 2001; Oettler et al. 2003). days to anthesis (AD), spikelets per spike (SS); grains As a cross between wheat and rye, the hexaploid per spike (GS), 1000-kernel weight (1000-KW), grain Triticale has one-third of its chromosomes from rye yield (GY), test weight (TW) and harvest index (HI). and might be expected to have a higher potential for The G1 and G4 parents showed better GCA for GY, HI, heterosis compared to the production of wheat hybrids 1000-KW and SL indicating a greater contribution of (Oettler et al. 2003). Pollen dissemination, pollen additive gene action and a promising feature to obtain supply, duration of flowering, and alogamy rate are prominent recombination lines. The G1xG4 cross showed higher in Triticale than in wheat, conditions which may Hh and a significant SCA value for GY, indicating a greater be favorable for the production of hybrids (Yeung and contribution of the non-additive gene action, useful to Larter 1972; Sowa and Krysiak 1996; Oettler et al. 2003). develop hybrids. The estimation of genetic parameters, such as heterosis and combining ability, allows inferences about the Keywords: Triticale, General Combining Ability, predominant action of the genes, indicates the appropriate Specific Combining Ability, Additive Genetic Effects, selection strategy to be applied in a breeding program, and Heterobeltiosis also facilitates the identification of the best parents. Diallel mating designs provide useful genetic information, such as general combining ability (GCA) and specific combining ability (SCA), to devise appropriate breeding and selection strategies. Griffing’s (1956) method partitions the genetic variability into an additive component (estimated by GCA) *Corresponding author: Enzo Ferrari, Faculty of Agronomy, National and a non-additive component (estimated by SCA). University of La Pampa, RN 35 km 334 (CP 6300), Santa Rosa, La Pampa, Argentina, E-mail: [email protected] High values of GCA show a greater proportion of Aurora Picca, Rodolfo Domínguez and Héctor Paccapelo, Faculty of Ag- additive genetic effect and an efficient gene transfer to ronomy, National University of La Pampa, RN 35 km 334 (CP 6300), progenies (Madic et al. 2005), whereas specific combining Santa Rosa, La Pampa, Argentina ability (SCA) detects the best hybrid combinations resulting

Open Access. © 2018 Enzo Ferrari et al., published by De Gruyter. This work is licensed under the Creative Commons Attribution-NonCommercial- NoDerivs 4.0 License. Heterosis and combining ability for yield and other agronomic traits in Triticale 39

from the non-additive effects of genes (Oettler et al. 2003; Yijk = µ + gi + gj + sij + eijk

Oettler et al. 2005; Yildirim et al. 2014). According to Grzesik where, Yijk is the mean phenotypic value, µ is the general and Wegrzyn (1998), the effect of GCA is more important mean, gi and gj are the GCA effect of each parent, sij is the for Winter Triticale grain yield than that of SCA, however, SCA effect of the hybrid and eijk is the experimental error. Oettler et al. (2003) found the opposite to be the case. The GCA and SCA effects were tested using the t-test Heterosis is the phenomenon by which F1, resulting (Ceballos 1996). The statistical analysis was carried out from the crossing of two genotypes, is higher in growth, using the Genes software (Cruz 2006). The relationship size, vigor and yield than the average of these genotypes GCA/SCA was analyzed as indicative of the contribution of (Gutiérrez et al. 2002). The term heterosis describes the additive and non-additive effects for all the variables increased size and yield in crossbred, compared to under study. The heterosis estimation with respect to the corresponding inbred lines (Shull 1948), while parents’ average was carried out using the Mh = 100 heterobeltiosis expresses improvement in relation to (F1-Mp)/Mp formula, where F1 = first generation from cross the better parent. Information regarding the amount of and Mp = average parent = (P1+ P2)/2. The heterobeltiosis heterosis in relation to grain yield and other agronomic estimation with respect to the best parent was carried traits is yet scarce for winter crops. Results from out as Hh = 100 (F1-Hp)/Hp, where F1 = first generation experiments with individual Triticale plants, or in small from cross and Hp = best parent. The t-test was used to plots, have been published (Grzesik and Węgrzyn 1998; determine whether F1 hybrid means were statistically Oettler et al. 2001; Yildririm et al. 2014). The present study significant for Mh and Hh means as follows (Wynne et al. was carried out using a diallel cross system among five 1970; Yildirim et al. 2014): genotypes of Triticale to assess the general and specific combining abilities and to discriminate the best F1 parents t (Mh) and hybrids that express superior heterosis.

t (Hh) 2 Materials and Methods where t(Mh) is the t-value for Mh; t(Hh) is the t-value for Hh; and Ems is the error mean square. Plant material: the advanced experimental lines CIMMYT 829 (G1), CIMMYT 830 (G2), CIMMYT 834 (G3), CIMMYT 820 Ethical approval: The conducted research is not related (G4) and the cultivar Antonio UNLPam (G5) were used as to either human or animal use. parents for half the diallel in this experiment. The F1 seeds from the 10 hybrids were produced manually by hand- emasculation and pollination in Santa Rosa, La Pampa, 3 Results and Discussion Argentina during 2015. On average, 10 seeds each for parents and hybrids were planted and grown to maturity 3.1 Diallel analysis in a greenhouse (10 x 15 lines = 150 entries), where they were randomly distributed in a completely randomized Table 1 shows the diallel analysis and parent and design during 2016. The phenotypes were collected from hybrid mean squares for the assessed traits. Significant 10 individual plants each, for both parents and hybrids, differences were found in the genotype’s source of and averaged. variation, which was true for SP (p<0.05), as well as Traits evaluated: data were recorded for the being highly significant for the rest of the traits (p<0.01), following traits: spike per plant (SP), spike length (SL, in showing the importance of examining variance among cm), days to anthesis (AD, unit days since emergence to genotypes. In the case of GCA, the differences found were flowering), spikelets per spike (SS), grains per spike (SG), considered highly significant for all assessed traits, except 1000-kernel weight (1000-KW, in g), grain yield (GY, in g for SP. In the case of SCA, they were highly significant (p < plant-1), test weight (TW, in g ml-1 and transformed to kg 0.01) for SL, SS, GS, 1000-KW, GY and HI; only significant hl-1) and harvest index (HI, in %). (p < 0.05) for AD and non-significant for SP and TW. Data analysis: the analysis of variance for studied The significance of the GCA and SCA effects show the traits was performed using the Info Stat software (Di presence of additive and non-additive genetic action, Rienzo et al. 2008). The diallel crosses were analyzed respectively; however, the GCA/SCA values suggest that following Griffing’s (1956), method 2, model 1 (fixed the effects of additive genetic action were more important effects): for the expression of these traits. From the point of view 40 E. Ferrari, et al. of germplasm identification within a program of genetic (66.99 kg hl-1) and HI (0.44%); G3 in GY (5.90 g pl-1) and improvement, both the GCA as well as the SCA effects may 1000-KW (47.58 g) and G5 in SP (3.50), AD (101.9 d) and be considered, depending on the specific objectives (De la SS (26.50). Among in F1 hybrids that stood out, G1 x G2 Cruz-Lázaro et al. 2010). cross in SL (13.05 cm), GS (63.40 ) and 1000-KW (49.21 The parents’ average and their 10 F1 crosses for the g); G1 x G4 in GS (59.60), GY (7.18) and HI (0.49); G2 x G3 nine traits analyzed are shown in Table 2. According in SP (3.90); G2 x G4 in TW (67.98); G2 x G5 in SL (14.10) to the characters analyzed, the parents who stood out and SS (29.70); G3 x G5 in SP (3.80) and SS (28.10); and were: G1 in SP (3.50), SL (11.95 cm), GS (56.90), TW G4 x G5 in SS (27.90).

Table 1: Mean squares of the diallel analysis of variance of five parental and 10 F1 progenies for nine agronomic traits Variation Source d.f. SP SL AD SS GS 1000-KW GY TW HI (cm) (unit days) (g) (g pl-1) (kg hl-1) (%)

Mean Square GCA 4 1,4ns 33,1** 1067,5** 134,8** 552,5** 808,4** 18,4** 359,3** 0,09** SCA 10 1,1ns 16,4** 80,4* 43,4** 316,9** 118,9** 4,5** 28,2ns 0,01** Genotypes 14 1,1* 21,2** 362,5** 69,5** 384,2** 315,9** 8,4** 122,8** 0,03** Error 135 0,7 1,3 26,8 8,47 83,4 28,7 0,9** 19,8 0,003 GCA/SCA 1,27 2,02 13,28 3,11 1,74 6,80 4,09 12,74 9,00 CV (%) 24,37 9,76 6,14 11,57 17,75 12,88 16,87 7,01 13,32 GCA = general combining ability; SCA = specific combining ability; CV = percent coefficient of variation; df = degrees of freedom; SP = spikes per plant; SL = spike length, AD = days to anthesis; SS = spikelets per spike; GS = grains per spike; 1000-TW = 1000-kernel weight; GY = grain yield; TW = test weight; HI = harvest index; *, ** significant at p < 0.05 and p < 0.01, respectively.

Table 2: Means of nine agronomic traits of five parents and their 10 crosses evaluated in Santa Rosa, La Pampa, during 2016 Parent and F1´s SP SL AD SS GS 1000-KW GY TW HI (cm) (unit days) (g) (g pl-1) (kg hl-1) (%)

G1 3.50 11.95 82.10 24.90 56.90 41.72 5.83 66.99* 0.44 G2 3.40 9.00 82.40 22.80 47.50 44.49 5.45 65.69 0.43 G3 3.00 11.08 86.60 24.50 51.40 47.58* 5.90 63.29 0.41 G4 3.30 9.45 81.30 19.30 46.80 37.98 5.57 65.04 0.40 G5 3.50 11.75 101.9** 26.50 40.70 41.60 2.98 54.75 0.24 G1 x G2 3.40 13.05* 78.30 27.00 63.40* 49.21* 6.27 63.30 0.46 G1 x G3 3.30 11.25 79.00 23.20 47.70 40.36 5.93 66.25 0.45 G1 x G4 2.90 12.55 79.80 25.00 59.60* 47.13 7.18* 65.82 0.49* G1 x G5 3.60 12.65 88.40 27.30 49.60 36.41 5.14 58.64 0.38 G2 x G3 3.90* 9.55 81.30 23.50 44.50 42.89 5.36 64.30 0.40 G2 x G4 2.80 10.50 81.50 23.40 56.90 35.23 6.46 67.98* 0.45 G2 x G5 3.30 14.10* 89.90 29.70* 54.40 42.41 5.71 62.00 0.37 G3 x G4 2.90 10.97 81.10 24.30 54.00 45.22 6.39 65.03 0.45 G3 x G5 3.80* 12.72 88.20 28.10* 45.70 43.91 5.24 59.75 0.38 G4 x G5 2.90 12.30 83.80 27.90* 53.00 27.22 5.91 63.48 0.40 Mean 3.30 11.52 84.37 25.16 51.47 41.55 5.68 63.49 0.41 σ 0.34 1.46 6.02 2.64 6.20 5.62 0.92 3.50 0.06 * higher than μ+σ, ** higher than μ+2σ. SP = spikes per plant; SL = spike length, AD = days to anthesis; SS = spikelets per spike; GS = grains per spike; 1000-KW = 1000-kernel weight; GY = grain yield; TW = test weight; HI = harvest index. Heterosis and combining ability for yield and other agronomic traits in Triticale 41

3.2 General and Specific Combining Ability 3.2.5 Grains per Spike Analysis In the GS trait, the G1 parent was the one with the most 3.2.1 Spike per plant significant GCA effect (3.61) whereas those showing the least effect were G5 (-3.53) and G3 (-2.02). In SCA, the G1 As far as the SP trait is concerned, parents showed non- x G2 (7.55) and G2 x G5 (5.70) crosses expressed positive significant values in GCA, and the G2 x G3 cross showed a effects. In this study, the correlation obtained between positive and significant effect of 0.53 in SCA (Table 3). This GS and GY was r = 0.78 (p<0.01) (Table 4). Yildirim et al. trait was both negatively and significantly associated with (2014) and Paccapelo et al. (2017) refer to this trait as an GS (r = -0.52, p<0.05) and GY (r = -0.57, p<0.05), showing important component of grain yield in Triticale. that an increase in the number of spikes per plant produces a decrease in the number of grains per spike and grain yield per plant (Table 4). Nevertheless, Yildirim et 3.2.6 1000-Kernel Weight al. (2014) refer to positive associations between SP and GY in Triticale. For the 1000-KW, the G4 (3.61), G3 (1.53) and G2 (1.20) parents had positive and highly significant GCA values. The G1 x G4 (3.43), G4 x G5 (3.04) and G2 x G5 (2.93) crosses 3.2.2 Spike Length expressed positive SCA effects. In this study, a correlation r = 0.13 (p<0.01) was found between 1000-KW and GY (Table In the case of SL, all parents proved to have a highly 4). This characteristic is directly associated with potential significant GCA effect; G5 (0.87) and G1 (0.61) had the grain yield in Triticale (Castro et al. 2011; Yildirim et al. highest values, which were transferred to the SCA crosses 2014; Paccapelo et al. 2017). G2 x G5 and G1 x G2 (1.48), coinciding with Reyes et al. (2004) and De la Cruz-Lázaro et al. (2010) who state that crosses with higher SCA are the result of crosses with, at 3.2.7 Grain Yield least, one high GCA parent. In GY, the G4 (0.42) and G1 (0.29) parents expressed positive GCA effects, and, in the case of SCA, positive and highly 3.2.3 Days to Anthesis significant values were found in crosses of G2 x G5 (0.82), G1 x G4 (0.78) and G4 x G5 (0.68). However, the G2 x G5 and G4 The negative correlation between AD and GY (r = -0.85, x G5 crosses had low yield averages due to the low additive p<0.01) (Table 4) indicates that it would be desirable contribution of the G5 parent, that shows forage ability. to reduce the number of days to anthesis. G4 (-2.49), G1 (-2.36) and G2 (-1.49) genotypes would decrease the number of days to anthesis as a result of being GCA 3.2.8 Test Weight negative. An early pollination provides a longer period for grain formation and development (Inamullah et al. In TW, significant GCA values were obtained in the G4 2006; Yildirim et al. 2014). The G4 x G5 cross was the (1.64), G2 (1.15) and G1 (1.01) parents, but none of the only one which resulted in a significant negative value crosses showed significant SCA values. This characteristic for SCA (-4.92). appeared to be strongly associated with grain yield per plant (r = 0.80, p<0.01) (Table 4).

3.2.4 Spikelets per Spike 3.2.9 Harvest Index In the case of the SS trait, it was found that the G5 parent presented the highest GCA effect (2.15) whereas G4 was The highest GCA values for HI were those of G1 (0.03) and both significant and negative, indicative of a decrease in G4 (0.02). The G4 x G5 cross had the highest SCA value. A this characteristic (-1.68). The F1 hybrids G2 x G5, G4 x G5 positive and highly significant association was found with and G1 x G2 were the ones with the highest SCA. grain yield (r = 0.95, p<0.01) (Table 4). 42 E. Ferrari, et al.

Those parents showing high GCA values for yield and transmitted to their progeny as a result of the importance of other agronomic characteristics of interest are the most additive effects. On the other hand, the crosses with higher promising ones to be incorporated into a program of genetic SCA values may be considered useful for the development improvement, due to the fact that those characteristics are of a hybrid program (De la Cruz-Lázaro 2010).

Table 3: Effects of general and specific combining ability for different traits in Triticale genotypes Parent and SP SL AD SS GS 1000-TK GY TW HI F1´s (cm) (unit days) (g) (g pl-1) (kg hl-1) (%)

Effect of general combining ability G1 0.06 0.61** -2.36** 0.19 3.61** -1.02 0.29** 1.01* 0.03** G2 0.06 -0.56** -1.49** -0.25 0.77 1.20* 0.08 1.15* 0.01 G3 0.01 -0.36** -0.49 -0.41 -2.02* 1.53** 0.08 0.14 0.01 G4 -0.24 -0.56** -2.49** -1.68** 1.18 3.61** 0.42** 1.64** 0.02** G5 0.11 0.87** 6.84** 2.15** -3.53** -5.32** -0.88** -3.94** -0.06** Effect of specific combining ability G1xG2 -0.01 1.48** -2.22 1.90* 7.55** -0.02 0.21 -2.34 0.01 G1xG3 -0.07 -0.53 -2.52 -1.74* -5.36* 2.42 -0.14 1.61 0.01 G1xG4 -0.21 0.98** 0.28 1.33 3.34 3.43* 0.78** -0.31 0.03 G1xG5 0.13 -0.36 -0.45 -0.20 -1.95 2.76 0.04 -1.92 0.00 G2xG3 0.53* -1.05** -1.09 -1.00 -5.72* -2.68 -0.49 -0.48 -0.03 G2xG4 -0.31 0.10 1.11 0.17 3.48 2.85 0.27 1.71 0.01 G2xG5 -0.17 2.26** 0.18 2.64** 5.70* 2.93* 0.82** 1.30 0.01 G3xG4 -0.17 0.36 -0.29 1.23 3.37 0.43 0.20 -0.24 0.01 G3xG5 0.37 0.68* -2.52 1.20 -0.22 -1.36 0.35 0.06 0.03 G4xG5 -0.27 0.46 -4.92** 2.27** 3.88 3.04* 0.68** 2.29 0.04** *, ** significant at p < 0,05 and p < 0,01, respectively. SP = spikes per plant; SL = spike length, AD = day to anthesis; SS = spikelets per spike; GS = grains per spike; 1000-KW = 1000-kernel weight; GY = grain yield; TW = test weight; HI = harvest index

Table 4: Correlation coefficients (r) for nine agronomic traits in Triticale genotypes r SP SL AD SS GS 1000-KW TW HI

SL -0.01ns AD 0.27ns 0.28ns SS 0.13ns 0.87** 0.46ns GS -0.52* 0.42ns -0.55* 0.20ns 1000-KW 0.18ns 0.04ns -0.09ns -0.04ns 0.18ns TW -0.44ns -0.40ns -0.87** -0.55* 0.50ns 0.01ns HI -0.43ns -0.10ns -0.94** -0.30ns 0.70** 0.18** 0.86** GY -0.57* 0.06ns -0.85** -0.16ns 0.78** 0.13** 0.80** 0.95** ns, * and **: nonsignificant, significant at the 0.05 and 0.01 probability levels, respectively SP = spikes per plant; SL = spike length, AD = days to anthesis; SS = spikelets per spike; GS = grains per spike; 1000- KW = 1000 kernel weight; GY = grain yield; TW = test weight; HI= harvest index Heterosis and combining ability for yield and other agronomic traits in Triticale 43

3.3 Heterosis and Heterobeltiosis 3.3.3 Spikelets per Spike

The SCA values for all the traits of each hybrid were For the SS trait, a highly significant Mh was found in checked against the Mh and Hh coefficients (Table 5). the G4 x G5 (21.83%), G2 x G5 (20.49%) crosses, and a significant for the G1 x G2 (13.21%) cross.

3.3.1 Spike Length 3.3.4 Grain per Spike There were diverse heterotic effects for spike length, the two top scoring F1 hybrids with significant positive values In GS, a significant Mh was found in the G2 x G5 (23.36%), being G2 x G5 and G1 x G2, with Mh of 35.90 and 24.58 G1 x G2 (21.46%), G4 x G5 (21.14%) and G2 x G4 (20.68%) percent, respectively. Only the G2 x G5 (20.00%) cross was crosses. Hh positive for this trait.

3.3.5 1000-Kernel Weight 3.3.2 Days to Anthesis As far as the 1000-KW trait is concerned, only the G1 x G4 For AD, the promising crosses were: G4 x G5 (-8.52), G3 x G5 (18.27%) and G1 x G2 (14.16%) crosses had a significant (-6.42) and G1 x G3 (-6.34) since they showed a statistically Mh. significant Mh in the reduction of the cycle to anthesis; none of the crosses showed a significant Hh.

Table 5: Estimation of percentage heterosis (Mh %) and heterobeltiosis (Hh %) for nine agronomic traits in F1 Triticale F1s SP SL AD SS GS 1000-KW GY TW HI

G1xG2 Mh(%) -1.45 24.58** -4.80 13.21* 21.46* 14.16* 11.17 -4.58 5.75 Hh(%) -2.86 9.21 -4.63 8.43 11.42 10.61 7.55 -5.51 4.55 G1xG3 Mh(%) 1.54 -2.30 -6.34* -6.07 -11.91 -9.61 1.11 1.70 5.88 Hh(%) -5.71 -5.86 -3.78 -6.83 -16.17 -15.17* 0.51 -1.10 2.27 G1xG4 Mh(%) -14.71 17.29** -2.33 13.12 14.95 18.27* 25.96** -0.30 16.67* Hh(%) -17.14 5.02 -1.85 0.40 4.75 12.97 23.16* -1.75 11.36 G1xG5 Mh(%) 2.86 6.75 -3.91 6.23 1.64 -12.60 16.69 -3.66 11.76 Hh(%) 2.86 5.86 7.67 3.02 -12.83 -12.73 -11.84 -12.46** -13.64 G2xG3 Mh(%) 21.88 -4.88 -3.79 -0.63 -10.01 -6.83 -5.55 -0.29 -4.76 Hh(%) 14.71 -13.81* -1.33 -4.08 -13.42 -9.86 -9.15 -2.12 -6.98 G2xG4 Mh(%) -16.42 13.82* -0.43 11.16 20.68* -14.56* 17.24 4.00 8.43 Hh(%) -17.65 11.11 0.25 2.63 19.79 -20.81** 15.98 3.49 4.65 G2xG5 Mh(%) -4.35 35.90** -2.44 20.49** 23.36* -1.48 35.47** 2.96 10.45 Hh(%) -5.71 20.00** 9.10 12.08 14.53 -4.68 4.77 -5.62 -13.95 G3xG4 Mh(%) -13.43 18.92 -0.92 15.44 14.53 9.66 15.97 -0.51 8.43 Hh(%) -12.12 -0.99 0.25 -0.82 5.06 -4.96 8.31 -0.02 9.76 G3xG5 Mh(%) 16.92 11.43* -6.42* 10.20 -0.76 -1.53 18.02 1.24 16.92* Hh(%) 8.57 8.26 1.85 6.04 -11.09 -7.71 -11.19 -5.59 -7.32 G4xG5 Mh(%) -14.71 16.04** -8.52** 21.83** 21.14* -31.59** 38.25** 5.99 28.13** Hh(%) -17.14 4.68 3.08 5.28 13.25 -34.57** 6.10 -2.40 2.50 SP = spikes per plant; SL = spike length, AD = days to anthesis; SS = spikelets per spike; GS= grains per spike; 1000-KW = 1000-kernel weight; GY= grain yield; TW = test weight; HI = harvest index. *, ** significant at p < 0.05 and p < 0.01, respectively. 44 E. Ferrari, et al.

3.3.6 Grain Yield Conflict of interest: Authors state no conflict of interest.

In GY, the crosses that were statistically significant for Mh were: G4 x G5 (38.25%), G2 x G5 (35.47%) and G1 x G4 References

(25.96%), while for Hh, G1 x G4 (23.16%) were important. Barary M., Warwick, N.W.M., Jessop R.S., Taji A.M., Osmotic Published papers mention Mh with values of 4.4 to 17.7% adjustment and drought tolerance in Australian triticales, In: (Oettler et al. 2001), -2.9 to 20.5% (Oettler et al. 2003) Proceedings of the 5yh International Triticale Symposium, and -11.4 to 22.4 % (Oettler et al. 2005), while Yildirim et Radzikow, Poland, 2002, 135-141 al. (2014) obtained values ranging from -11.72 to 30.36%. Castaño M., Ferrari E., Ribotta P.D., Ferreira V., Grassi E., Ferreira A., di Santo H., Castillo E., Paccapelo HA., Aptitud de las harinas According to Oettler et al. (2003), the results from single- integrales de diferentes triticales (x Triticosecale Wittmack) plant experiments or small plots tend to overestimate para la elaboración de galletitas. Semiárida, 2015a, 25(1), heterosis. 25-39 Castaño M., Ribotta P., Ferreira V., Grassi E., Ferreira A., di Santo H., Castillo E., Ferrari E., Paccapelo H, Análisis del perfil fisico- 3.3.7 Test Weight químico de las harinas de triticales (x Triticosecale Wittmack) y su relación con la elaboración de galletitas de calidad. Senasa, 2015b, 1(9), 1-14 In TW, it was found that crosses with Mh ranging from Castro N., Dominguez R., Paccapelo H., Análisis del rendimiento de -4.58 to 5.99 did not have statistical significance. Oettler et grano y sus componentes en cereales sintéticos (Tricepiros y al. (2005) found a range of Mh values between -2.4 and 7.1 Ttriticales). Rev. Facultad de Agronomía, UN La Pampa, 2011, % and for Hh between -5.0 to 4.1 %. 22, 13-21 Cruz C.D., Programa Genes: Biometría. Editora UFV, Viçosa (MG), 2006 De la Cruz-Lázaro E., Castañón-Najera G., Brito-Manzano N.P., 3.3.8 Harvest Index Gómez-Vázquez A., Robledo-Torres V., Lozano del Río AJ., Heterosis y aptitud combinatoria de poblaciones de maíz In HI, significant Mh was found in the G4 x G5 (28.13%), tropical. Phyton, 2010, 79, 11-17 G3 x G5 (16.92%) and G1 x G4 (16.67%) crosses. Di Rienzo J.A., Casanoves F., Balzarini MG., Gonzalez L., Tablada M., Robledo CW., InfoStat, versión 2008. Grupo InfoStat, The G1 x G4 cross displayed outstanding behavior and Universidad Nacional de Córdoba, 2008 significant Hh in GY values, a trait which is considered as Griffing B., Concept of general and specific combining ability in more relevant in terms of genetic improvement for hybrids, relation to diallel crossing systems. Aust. J. Boil Sci., 1956, 9, and it also showed significant Mh values for HI, 1000-KW 463-493 and SL. This cross, in turn, showed significant SCA values Grzesik H., Węgrzyn S., Heterosis and combining ability insome varieties of triticale. Proc. 4th Int. Triticale Symp., Red Deer, for GY, 1000-KW and SL. The coinciding significant values 1998 2, 129-133 of heterosis and SCA reinforce the notion that they are Gutiérrez R.E., Palomo A., Banda A., Lázaro E. Aptitud combinatoria determined by a non-additive genetic action (dominance y heterosis para rendimiento de líneas de maíz en la Comarca and interaction). Lagunera. Revista Fitotecnia Mexicana, 2002, 25, 271-277 (in Spanish) Inamullah H.A., Mohammadi F., Din S.U., Hassan G., Gul R., 4 Conclusions Evaluation of the heterotic and heterobeltiotic potential of wheat genotypes for improved yield. Pakistan J. Bot., 2006, 38, The diallel analysis among the five Triticale lines showed 1159-1167. Oettler G., Becker H.C., Hoppe G., Heterosis for yield and other that additive gene effects were of the greatest importance agronomic traits of winter triticale F1 and F2 hybrids. Plant for the following traits: SL, AD, SS, GS, 1000-KW, GY, TW Breeding, 2001, 120, 351-353 and HI. The G1 and G4 parent produced the highest values Oettler G., Burger H., Melchinger A.E., Heterosis and combining of GCA in GY, HI, 1000-KW and SL, indicating a greater ability for grain yield and other agronomic traits in winter contribution of genetic additive action and turning them triticale. Plant breeding, 2003, 122(4), 318-321 Oettler G.S., Tams H., Utz H.F., Bauer E., Melchinger A.E., into a promising tool to obtain recombination lines. The Prospects for hybrid breeding in winter triticale: I, Heterosis G1 x G4 cross was outstanding for its GY, GS and HI, and and combining ability for agronomic traits in European elite also due to its significant Hh values and SCA values in GY, germplasm. Crop Sci., 2005, 45:1476-1482 indicative of a greater contribution of the non additive Oliete B., Pérez G.T., Gómez M., Ribotta PD., Moiraghi M., León AE., genetic action, which would deem them suitable for the Use of wheat, triticale and rye flours in layer cake production. development of a hybrid program. Food Science & Technology, 2010, 45, 697-796 Heterosis and combining ability for yield and other agronomic traits in Triticale 45

Madic M., Paunovic A., Durovic D., Kraljvic-Balalic M., Knezivic D., Shull G.H., What is heterosis? Genetics, 1948, 33, 439–446 The analysis of gene effect in the inheritance of kernel number Sowa W., Krysiak H., Outcrossing in winter triticale. In: Triticale: per spike in barley hybrid. Genetika, 2005, 37, 261-269 Today and Tomorrow, Kluwer Academic Publishers, 1996, Paccapelo H., Ferreira V., Picca A., Ferrari E., Domínguez R., Grassi 593-596 E., Ferreira A., di Santo H., Castillo E., Triticale (x Triticosecale Wynne J.C., Emery DA., Rice PH., Combining ability estimation in Wittmack): rendimiento y sus componentes en un ambiente Arachis hypogaea L. II. Field performance of F1 hybrids. Crop semiárido de la Argentina. Chilean journal of agricultural & Sci., 1970, 10, 713–715 animal sciences, 2017, 33(1), 45-58 Yeung KC., Larter EN., Pollen production and dissemination Pena R.J., Food uses of triticale. Triticale improvement and properties of triticale relative to wheat. Can. J. Plant Sci., 1972, production, In Triticale improvement and production. FAO, 52, 569-574. 2004, 37-48 Yildirim M., Gezginc H., Paksoy AH., Hybrid performance and Reyes D., Molina J.D., Oropeza MA., Moreno EDC., Cruzas dialélicas heterosis in F1 offspring of triticale (x Tricosecale Wittmak). entre líneas autofecundadas de maíz derivadas de la raza Tourkish Journal of Agriculture and Foresty, 2014, 38, 877-886 tuxpeño. Revista Fitotecnia Mexicana, 2004, 27(1) (in Spanish)