Origin

In recent years, there has been progress in the field of the induction of mutations in breeding, hundreds of mutants have been released as new cultivars. In rice, ^{Micke et al. (1990a)} reported the release, up to that time, of 251 new varieties of rice, developed with the use of induced mutations, and about 1 300 varieties of different species, 90% using cobalt-60 radiations (^{Micke et al., 1990b}), for this reason this is a technique widely used to create genetic variability (^{Kihupi, 1984}).

In 1998, at the National Institute of Forestry, Agriculture and Livestock Research (INIFAP), the improvement of rice by induction of mutations was started, for this, seed of the variety Morelos A-92 was irradiated, in the National Institute of Nuclear Research (ININ), as a result, the M3 mutant was detected as outstanding, but not with sufficient quality parameters to release it, but to use it as a progenitor in the breeding program (^{Salcedo and Barrios, 2012}).

The process to obtain the variety Morelos A-2016 began in 2005 at the INIFAP Campo Experimental Zacatepec, Morelos. The parents used were the CAEZ116-1111-97 line and the M3 mutant. After crossing, the progeny obtained was evaluated during the following years. In 2006 and 2007, massive harvests were carried out and subsequently three consecutive genealogical selections were carried out (2008-2010). In 2011, a preliminary performance test was carried out on several groups of lines, around 256 materials, from which C14Za06 was identified as outstanding (currently, Var. Morelos A-2016). In 2013, 51 lines were sown according to the preliminary test, this in order to increase seed and perform the industrial quality test.

During 2014 and 2015, evaluations were carried out in the field, together with five other lines and a commercial control, Morelos A-2010, after each harvest the grain milling quality was evaluated in the laboratory of industrial quality analysis for rice in the Experimental Field Zacatepec (^{Tavitas et al., 2009}) and in the rice mill of Jojutla, for commercial evaluation. The results obtained indicated good response of the grain in the grinding process. Cycles 2014 and 2015, with the support of cooperating producers, the line was evaluated in different environments of the state of Morelos: Jojutla, Emiliano Zapata, Mazatepec, Coatlan del Río and Cuautla, main rice producing areas.

Field results and laboratory analysis indicated good industrial aptitude of line C14Za06. It showed stability in the different environments of the region obtaining high grain yield (>10 t ha^-1), moderate resistance to pyricularia or grain avalanche (disease caused by the fungus Magnaporthe grisea) (^{Hernández et al., 2012}), habit of erect growth, height of plant of 130 cm, resistance to lodging, good milling quality (59% of whole grain) and with Morelos type grain characteristics. In 2016, a batch was established for the production of original seed and the process for the registration of the Morelos A-2016 variety began (Table 1).

Description of the variety Morelos A-2016

For the description of the agronomic and morphological characters of the variety Morelos A-2016 some records were made in the field and others in the industrial quality analysis laboratory of rice, during the spring-summer (PV) 2015 and PV-2016 cycles. For the varietal description in the field, samples were taken at random in a lot established in the Experimental Field Zacatepec, Morelos.

The agronomic and morphological characteristics were described in accordance with the guide established by the International Union for the Protection of New Varieties of Plants (^{UPOV, 2004}). As a comparative reference, the characteristics of the variety Morelos A-2010 were taken, the records obtained are shown in Table 2.

Maturity

Conclusions

The generation of new varieties of rice is important because diseases affect a greater proportion of old varieties; with this variety with tolerance to diseases, it will help to reduce cultivation costs by avoiding the use of chemical products.