Obtaining the variety and characteristics

The variety of bread wheat (Triticum aestivum L.) Don Carlos M2015 is of spring habit and the experimental line was obtained in the breeding program of temporary wheat of the INIFAP-CEVAMEX, later that line was evaluated in the nurseries and trials national yields of wheat of temporary that implements year after year the indicated program. The line was obtained by hybridization, where a simple cross was made between the BABAX*2/PRL experimental line and the Tlaxcala F2000 variety and later the homozygous selection was developed through the mass method.

The simple cross between its two parents occurred in the autumn-winter cycle (A-W) 2001-2002 in Chapingo, State of Mexico and was identified with the number TC020537, which was planted in its F₁ generation also in Chapingo, State of Mexico during the spring-summer cycle (S-P) 2002 under regular seasonal conditions and was harvested massively. The F₂ generation was planted in Roque, Guanajuato in 2002-2003 (A-W) cycle under conditions of limited irrigation (an irrigation of relief) and was harvested massively (0R). The F₃ generation was evaluated in Chapingo, State of Mexico during the 2003 P-V cycle under regular seasonal conditions and the population was massively harvested (0C).

The F₄ generation was planted in Roque, Guanajuato in 2003-2004 A-W cycle under normal irrigation conditions (three irrigation aid) and the population was harvested massively (0R). In its F₅ generation the population was planted in Chapingo, State of Mexico under favorable weather conditions in the 2004 P-V cycle where plant No. 16 (16C) was selected and harvested individually, this plant was planted in its F6 generation in Roque, Guanajuato in the 2004-05 A-W cycle under normal irrigation conditions, and where it was harvested massively (0R).

His genealogy and pedigree are the following:

BABAX*2/PRL//TLAXCALA

TC-020537-0R-0C-0R-16C-0R

The indicated experimental line was evaluated during the 2005 S-P cycle in the preliminary yield test (PPR) in four localities of the states of Tlaxcala and Mexico, later during the 2006 S-P cycle it was evaluated in the national nursery of selection of temporary wheat (VSTHT). From the summer of 2007 to 2011 it was tested in the national trials of wheat yield of rainfed (ERTHT) in about 60 different trials and compared against the varieties Tlaxcala F2000, Náhuatl F2000, Juchi F2000 and Rebeca F2000, which exceeded in grain yield, from 2012 to 2015, it was decided to compare the experimental line against the 11 varieties planted in the different regions producing wheat in temperate Mexico (information presented in Table 4) and also stood out with respect to the varieties control by its greater grain yield in different conditions of rainfed production and by its greater resistance to diseases.

Reaction to diseases

In the Table 1 presents agronomic and phytopathological information of Don Carlos M2015 and the control varieties, where it is observed that this new variety reaches physiological maturity on average at 111 days, being located within the intermediate cycle genotypes; it is resistant to lodging and showed resistance to leaf rust, moderate resistance to moderate susceptibility to yellow rust and tolerance to foliar disease complex. Regarding its reaction to diseases, it was located as the genotype with greater resistance to the two rusts and tolerant to the foliar disease complex, which places it from the phytopathological point of view, as the most suitable variety for seasonal sowing.

Don Carlos M2015, has the specific race resistance genes to leaf rust Lr1, Lr10, Lr16, Lr17 and Lr23. These genes are effective in seedling status to the races CBJ/QB, CBJ/QL, CBJ/QQ (^{Huerta-Espino and Singh, 1994}), LCJ/BN, BBG/BP, TCT/QB, TBD/TM, TCB/TD, MCJ/QM y MFB/SP (Singh, 1991). However, only Lr16 is effective in the seedling of the MBJ/SP and MCJ/SP breeds, which are the most common in Mexico since their identification in 1994 (^{Villaseñor et al., 2003}). In adult plants, the resistance of Don Carlos M2015 is based on the action of the Lr34 genes, which confers resistance to leaf rust and other foliar diseases (Kratinger et al., 2009), and the Lr46 gene.

Don Carlos M2015, is susceptible in seedling to the race of yellow rust CMEX14.25 one of those that overcame the resistance of Nana F2007 during 2014. However, the low degrees of severity registered in the variety Don Carlos M2015 in field (minors of 30%) when artificial inoculations are made with the isolates CMEX14.25, MEX14.141 and MEX14.146 (identified during 2014 that overcame the resistance of Nana F2007 and combine virulence for the genes Yr2, Yr3, Yr6, Yr7, Yr8, Yr9, Yr17, Yr27 and Yr31 among others), indicate that the new variety bases its resistance to yellow rust on at least three slow-growing genes in adult plants, two of them Yr18 and Yr29, the first with pleiotropic effect at Lr34 and the second to Lr46 (^{William et al., 2003}), both associated with the burning of the tip of the leaf.

Losses in grain yield due to the incidence of foliar diseases and yellow rust recorded in studies with the control and without the control of diseases in the variety Don Carlos M2015 and the varieties witnesses Altiplano F2007, Tlaxcala F2000 and Nana F2007 are presented in Tables 2 and 3, where it is observed that in this new variety there were losses of 18% and 16%, respectively, which were lower than those registered in the control varieties.

Performance potential

In the Table 4 presents the comparison of grain yield of Don Carlos M2015 and the control varieties, where it is observed that it exceeded the overall yield of all the control varieties of 9.5% (Altiplano F2007) up to 30.6% (Nana F2007); it is worth noting the fact that only the Altiplano F2007 variety competed with the new variety.

In conditions of favorable environments, Don Carlos M2015 also outperformed all the control varieties with differences that were 9.7% (Altiplano F2007) up to 30.5, 31.1, 32.3 and 32.7% with the varieties Triunfo F2004, Nana F2007, Batán F96 and Juchi F2000. In intermediate environments, the differences with the controls varied from 7.8% (Altiplano F2007) to 27.1, 27.8, 28.8, 33.4% with the varieties Juchi F2000, Náhuatl F2000, Gálvez M87 and Nana F2007, respectively. In conditions of critical environments Don Carlos M2015 presented a behavior similar to the other conditions, since it exceeded in yield all the control varieties, although in this condition, the differences were 12% (Altiplano F2007) up to 24.3, 24.7, 25.2, 26.7 % with the varieties Nana F2007, Juchi F2000, Gálvez M87 and Náhuatl F2000.

Industrial quality

Don Carlos M2015 is characterized by having hectoliter weights greater than 75 kg hL^-1, similar to the Altiplano F2007 and Náhuatl F2000 control varieties. Its grain is red and its hardness is classified as hard grain by its percentages lower than 47%. Due to its force values (W) of the mass between 200 and 300 x 10^-4 J it is classified as medium gluten and because of its relationship between toughness and extensibility (PL< 1) less than unity is extensible mass which combined with its grain hard texture allows you to get good bread volume of 800 mL with values similar to the control variety Altiplano F2007. The flour of this variety is suitable for baking in semi-mechanized or manual industry and as an improver of tenacious and strong masses in the mechanized industry.

Conclusions

Don Carlos M2015 is a variety that adapts to all producing regions of rainfed wheat in Mexico, since it is widely adapted that can be planted in favorable or rainy environments (more than 500 mm), intermediate or rainy (between 300 to 500 mm) and critical or erratic (less than 300 mm) in the states of Oaxaca, Puebla, Tlaxcala, Hidalgo, Mexico, Guanajuato, Jalisco, Zacatecas, Durango and Chihuahua.