Selection and population improvement on S1 non-progeny recurrent selection in Kareing Uthai native small-ear waxy corn variety

Abstract

Our research endeavors to enhance the population of the Kareing Uthai native small-ear waxy corn variety, aiming for uniformity, increased ear abundance, higher yields, and superior quality. Selection and improvement of the population were conducted between 2018 and 2019 through three cycles of S1 non-progeny recurrent selection. This process resulted in the enhancement of four populations, each derived from three cycles. Each cycle involved three selection steps: 1) selfing pollination of the population, 2) bulk-full sib pollination of the population, and 3) open pollination of the population. In total, 24 plots were utilized, each comprising six rows, 5 m in length, with a spacing of 0.75 m between rows and 0.25 m between plants, resulting in 120 plants/plot. The base population (C0) and three improved populations (C1, C2, and C3), alongside four commercial check varieties (Tein Nampueng, Tein Khaow, Tein Lai-52, and Tein Leang Khonkaen), were evaluated using a randomized complete block design (RCBD) with three replications during the rainy season of 2022 at the Uthai Thani Agriculture Research and Development Center. Our findings indicate significant improvements in both unhusked and husked yield of the C3 population compared to the C0 population, with increases of 691 and 397 kg/rai, respectively, representing a 74.9% and 55.4% enhancement, respectively. Additionally, the C3 population demonstrated notable increases in total ear number, ear number at the first ear position, and ear number at the second ear position compared to the C0 population, showing increases of 5,417, 4,233, and 1,185 ears/rai, respectively, corresponding to enhancements of 59.6%, 113.6%, and 22.1%, respectively. Furthermore, the C3 population exhibited a higher total number of ears compared to all commercial varieties, namely Tein Namphoung, Tein Kaow, Tein Lai-52, and Tein Leang Khon Kaen, with respective ear counts of 338, 112, 3,386, and 451 ears/rai.