2022 Volume 2022 Issue 10 Pages 21-32
‘Italian ryegrass Chukanbohon Nou 3 Go’ (hereinafter called ‘Nou 3 Go’), a diploid and early parental Italian ryegrass (Lolium multiflorum) cultivar with low nitrate-nitrogen concentration, was registered in 2011. The cultivar was developed by phenotypic recurrent selection of nitrate-nitrogen concentration in the seedlings and adult plants for five cycles. The plants showed more than 30 % reduction in nitrate-nitrogen concentration compared with that of ‘Yushun’. Heading date of the plants was similar to that of ‘Hataaoba’, and dry-matter yield of the plants was similar to that of ‘Hataaoba’ and ‘Yushun’. The F1 progenies from crosses of ‘Nou 3 Go’ with existing cultivars contained nitrate-nitrogen concentrations intermediate between those of the parents. This shows that the trait of low nitrate-nitrogen concentration in ‘Nou 3 Go’ is easily attached to an existing cultivar and line. ‘Nou 3 Go’showed lower nitrate-nitrogen and higher amino acid-nitrogen translocation in the xylem from the roots to the shoots compared with that of the parental generation, despite that the amount of nitrate-nitrogen uptake by the roots was not affected. Nitrate-nitrogen concentration in ‘Nou 3 Go’ in detached shoots was also lower than that of the parental generation. The low nitrate-nitrogen concentration of ‘Nou 3 Go’ reflects decreased root-to-shoot transport of nitrate-nitrogen and reduced capability for nitrate-nitrogen accumulation in the shoots.
