Genetic diversity and path analysis for nitrogen use efficiency in popcorn inbred lines
- PDF / 359,533 Bytes
- 9 Pages / 547.087 x 737.008 pts Page_size
- 77 Downloads / 208 Views
Genetic diversity and path analysis for nitrogen use efficiency in popcorn inbred lines Gabriel Borges Mundim • Jose´ Marcelo Soriano Viana • Ciro Maia • Geı´sa Pinheiro Paes • Rodrigo Oliveira DeLima
Received: 16 August 2012 / Accepted: 6 December 2012 / Published online: 15 December 2012 Ó Springer Science+Business Media Dordrecht 2012
Abstract Popcorn inbred lines with more efficient nitrogen use are better able to uptake nitrogen from the soil and convert it into higher grain yield, resulting in lower environmental and economic impacts caused by nitrogen fertilization. The objectives of this study were to (i) identify inbred lines superior in nitrogen use (ii) assess the genetic diversity between popcorn inbred lines under high and low N conditions and (iii) investigate the causal effects of several traits in nitrogen use efficiency (NUE). We evaluated 25 popcorn inbred lines under high and low N, and several traits related to NUE and its components were measured. Efficient and inefficient inbred lines under both N levels were identified and can be useful for generating a segregating population for quantitative trait loci mapping. The genetic diversity assessment based on phenotypic traits grouped the inbred lines into four clusters under both N levels, and the efficient inbred lines were grouped together, as were the inefficient lines. The most divergent inbred lines under high N were classified as efficient and intermediate and can be useful to generate a divergent breeding population with a high frequency of favorable genes for NUE. Nitrogen uptake efficiency (NUpE) was considered the most important trait for NUE. To improve the
G. B. Mundim (&) J. M. S. Viana C. Maia G. P. Paes R. O. DeLima Departamento de Biologia Geral, Universidade Federal de Vic¸osa, Vic¸osa, MG 36570-000, Brazil e-mail: [email protected]
accuracy of selection for NUE, a selection index involving the total root length (TRL), daily growth and NUpE traits under both N levels is recommended, as these traits had high correlations with and direct effects on NUE. Keywords Abiotic stress Genetic variability Root and shoot traits
Introduction Nitrogen use efficiency (NUE) can be defined as the ratio between grain yield per unit of nitrogen available to plants and is a function of nitrogen uptake efficiency (NUpE) and nitrogen utilization efficiency (NUtE). NUpE is defined as the ratio between the quantities of nitrogen absorbed and applied, while NUtE corresponds to the ability of a particular genotype to convert the absorbed nitrogen into biomass or grain yield (Moll et al. 1982). In studies conducted during the early stages of plant development, NUE is usually estimated based on shoot dry weight instead of grain yield. A given genotype is considered efficient if it produces satisfactorily under low nitrogen availability (Good et al. 2004). According to Hirel et al. (2007), increased NUE can be obtained by increasing any of its components. Increased NUpE can be achieved through modifying root morphological traits, whil
Data Loading...
