Quantitative studies on heterosis and inbreeding depression in maize (Zea mays l.)

Abstract

Abstract:The present investigation was carried out for studying heterosis and inbreeding depression of twenty eight hybrids (F 1 ʼ s) and their F 2 ʼ s made by crossing of eight maize inbreds in all possible cross combinations excluding reciprocal. Observations were recorded on ten quantitative traits viz., plant height (cm), ear length (cm), ear girth (cm), number of kernel rows per ear, number of kernels per row, 100 kernels weight (g) yield per plant (g), days to 50 % tassel emergence, days to 50% silk emergence and days to 50% maturity. Variable magnitude of heterosis was observed for different cross combinations for all the traits. Based on higher mean performance (94.33 to 118.67 g/plant) and higher heterotic response (11.95 to 30.48%) eleven crosses were selected. Response of inbreeding depression was significant in positive direction for most of the traits. Among these eleven crosses five crosses CM 300 x CML 142, CM 300 x CML 144, CM 300 x CML 150, CM 300 x CML 176 and CML 150 x CML 144 were selected having high heterotic value (12.31 to 30.48%) and lower inbreeding depression (less than 15%) for their utilization in maize improvement programme for the development of superior inbred lines.

Study on Per Se Performance and Heterosis for Green Cob Yield and Its Attributing Traits in Sweet Corn (Zea Mays L. Saccharata)

“…The hybrid L 2 x T 2 (58.03 %) manifested maximum standard heterosis, followed by hybrid L 1 x T 1 (52.35%) . The significant better parent heterosis and standard heterosis for green cob yield were also reported by Lahane et al (2015), Patel et al (2019), Kumari et al (2018), Gami et al (2018) and Chavan et al(2022). None of the hybrids under study recorded significant standard heterosis for cob length.…”

Studies of heterosis and inbreeding depression on maize (Zea mays L.)

“…Similar findings were also reported in maize byKumar and Babu (2019),Kumari et al (2018),Darshan and Marker (2019) andSolomon et al (2020). The cross CML-171 × BHU-N6 exhibited the highest negative significant economic heterosis for the traits, days to 50% tasselling and days to 50% silking in spring.…”

“…In the case of maize, there is much room for genetic improvement due to the abundance of variability in their germplasm (Om Prakash et al, 2019). Before designing genetic improvement techniques, it is necessary to understand various traits of interest (both qualitative and quantitative attributes) and their genetic regulation (Kumari et al, 2018). Increasing maize production requires the exploitation of heterosis.…”

Evaluasi keragaman genetic berbagai galur murni jagung manis utnuk penentuan tetua hibrida

“…Terjadinya penurunan tinggi tanaman dan hasil tanaman jagung merupakan akibat dari inbreeding depression dari populasi jagung S1 (generasi hasil selfing pertama) yang masih heterozigot sampai dengan S5 (generasi hasil selfing kelima) yang memiliki homozigositas tinggi (Ali et al, 2019). Terdapat inbreeding depression sebesar 2.46 -16,80% pada tinggi tanaman populasi jagung F2 dibandingkan populasi F1 atau hibridanya (Hussein & Mohammed, 2018;Kumari et al, 2018). Jagung manis merupakan tanaman menyerbuk silang yang umumnya memiliki heterosis dan inbreeding depression yang tinggi dibandingkan tanaman menyerbuk sendiri.…”