Selection response for oil content and agronomic performance in four subtropical maize populations


High oil content (HOC) maize (Zea mays L) genotypes may have an economic impact on animal husbandry and on food and feed industries in several countries due to their related high digestible energy value. Almost all knowledge about cultivating oil accumulation in maize kernels, using recurrent selection, have been generated in temperate regions, but very little is known about the genotypes commonly grown in subtropical regions. With the intention of developing the HOC in a subtropical maize germplasm in Celaya Mexico in 2004, a half-sib recurrent selec- tion scheme was initiated using near infrared spectrophotometry in four Bajio and Northwest varieties of white and yellow kernel populations (BWP, NWP, BYP, and NYP). With the aim to study the selection response for oil content, grain yield and other traits, field experiments conducted during 2011 in Morelia, and during 2011 and
2012 in Celaya. Results by location and combined across locations showed no significant changes within popula- tions in terms of grain yield and other agronomic characteristics, which is in contrast to the literature (grain yield has been show to decline as oil content increased). This response is due to the employed field selection criteria, which emphasized selecting healthy, top-yielding and agronomically superior individuals from each population. Regarding the oil content, a gradual increase over several cycles was obtained in the selected populations, us- ing a selection gain per cycle of 0.31%, 0.40%, 0.27%, and 0.30% for BYP, NYP, BWP, and NWP, respectively. These improved populations contained final oil contents of 7.5%, 8.1%, 7.6%, and 6.7%, for BYP, NYP, BW, P, and NWP, respectively.


Zea mays L, high oil content, selection response, recurrent selection, subtropical maize

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