Construction of a SSR linkage map and mapping of quantitative trait loci (QTL) for leaf angle and leaf orientation with an elite maize hybrid

Abstract

Maize (Zea mays L.) breeders have begun selecting for more compact plants for higher density planting in order to increase yield per unit area. Leaf angle and leaf orientation are very important traits affecting maize plant type (compactness). In this study, a genetic linkage map containing 138 simple sequence repeat (SSR) markers was constructed based on a mapping population consisting of 500 F2 individuals from the cross between inbred lines Ye478 and Dan340. This SSR linkage map spans a total of 1 394.9 cM with an average interval of 10.1 cM. Quantitative trait loci (QTL) for leaf angle and leaf orientation were identified in 397 F2:3 families. Six QTL for leaf angle were detected that could explain 41.0% of the phenotypic variation; while, eight QTL were detected for leaf orientation that could explain 60.8% of the phenotypic varia-tion. Single QTL contribution to phenotypic variation ranged from 2.9% to 13.6%. Additive and partial dominance were the main genetic effects for leaf angle and leaf orientation; in addition, nine pairs of locus interactions were detected for the two traits, indicating that epistatic interactions at the two-loci level also play a measurable role in the genetic basis of the two traits.

Identification of QTL for leaf angle and leaf space above ear position across different environments and generations in maize (Zea mays L.)

“…However, the genetic mechanisms of leaf angle and leaf space were not well known. Only a few studies for the QTL detection for leaf angle and leaf space in maize have been published (Mickelson et al 2002;Yu et al 2006;Lu et al 2007;Ku et al 2010;Zhang et al 2010;Tian et al 2011;Ku et al 2012;Zhu et al 2013;Zhang et al 2014). Moreover, the detection in one generation and single environment did not result in consistent QTLs (Boer et al 2007;Peng et al 2011).…”

“…Yu et al (2006) detected nine QTLs for LA on chromosomes 1, 2, 3, 8, 9 and 10 in two F 2:3 populations derived from H21 9 Mo17 and Zi330 9 K36. Lu et al (2007) detected six QTLs for LA in a F 2:3 family derived from the cross Ye478 9 Dan340, two of which located on chromosomes 1 and 3 explaining 10.8 and 11.2 % of phenotypic variation, respectively. Ku et al (2010) identified three QTLs for LA on chromosomes 1, 2 and 5 with the contribution to phenotypic variation ranging from 7.3 to 20.4 % in a F 2:3 population derived from Yu82 9 Mo17.…”

Genetic analysis of agronomic traits associated with plant architecture by QTL mapping in maize

“…For the traits related to plant architecture, PH and EH have been frequently studied (Kraja and Dudley, 2000;Sibov et al, 2003;Lima et al, 2006;Malosetti et al, 2008;Bai et al, 2010), and a large number of QTLs were found to be located in different chromosomal regions. There are also many reports on QTL identification of the LN trait (Jiang et al, 1999;Lima et al, 2006;Tang et al, 2007;Wang et al, 2008), and several studies have been performed on the LA and LO traits (Mickelson et al, 2002;Lu et al, 2007;Ku et al, 2010). Therefore, QTL mapping of traits associated with plant architecture is very significant in maize.…”

Association Analysis of Candidate Quantitative Trait Loci for Resistance to Banded Leaf and Sheath Blight in Maize

“…These loci were detected in the BLSB resistance research, which may be attributed to the theory that they affect maize resistance to different disease via the same regulation mechanism such as the Programmed Cell Death and cell-wall thickening, and their specific was of involvements in the maize resistance can be further identified by physiology and biochemistry researches. The particular cases are as follows: the previous studies indicated that bnlg1909 involved in maize From the prospect of loci distribution in chromosomes, loci were detected in all the chromosomes except photosynthesis via regulating the synthesis of chlorophyll a and b [27]; bnlg1017 involved in construction of maize plant type by affecting leaf angle, leaf direction, plant height and height of ear [28], [29]; bnlg1525 involved in drought tolerance [30]. The possible reason for their involvements in BLSB resistance might be as follows: bnlg1909 improved the efficiency of photosynthesis to provide energy for disease resistance [27]; bnlg1017 reduced the infection probability via regulating the angle to make it difficult for germs to invade sheath [31], this may be attributed to the phytopathology theory that BLSB germ infect the plant by invading the sheath initially, the it elevated the ear height to reduce the possibility of ear infection to reduce the effect on maize quality; bnlg1525 involved in the abiotic stress [25], the mechanism may be that according to the physiology and biochemistry researches for drought tolerance, osmotic pressure adjustments, including cell-wall thickening, were involved in the drought tolerance, and the BLSB infection also causes dehydration and degreasing, thus those loci involved in drought tolerance may get involved in maize resistance to BLSB via these methods.…”