Heterosis Analysis For Plant Traits Basing On Test Populations Of The Single Segment Substitution Lines In Maize

A set of single segment substitution lines(SSSLs)population,which derived for an elite inbred line 1x9801 as recurrent parent and inbred line Chang 7-2 as nonrecurrent parent,were used as marital for constructing test populations with elite inbred lines Z58,9058 and T7296.The SSSL and its three test population were evaluated at Xunxian and Changge location in two years,and the QTL and heterotic loci for plant height and ear height were analyzed.The main results were as follows:1.QTL mapping for plant height and ear height in the SSSL populationSSSL population was used as marital for QTL mapping related to plant height and ear height,a total of 21 QTL for plant height(PH)and 20 QTL ear height(EH)were identified in the two sites in two years.Out of them,9 PH were detected repeatedly in diffident sites,and the QTL qPHle,qPH3a,qpH3c and qPH4 were detected in four environments simultaneously,qPHlb,qPH6c,qPH7b,qPH8 and qPH9a identified concurrently in two environments.7 EH were detected repeatedly in multiple environments,and the single segment substitution line S49 including the qEH3a was identified in four environments simutansouly,meanwhile qEHlc and qEH3c were detected in three sites,while qEH6d,qEH7a,qEH7b and qEH9c were identified in two sites.The single segment substitution lines S49,S73 and S145 detected PH and EH at the same time,as qPH3a and qEH3c(bin3.02).qPH3c和qEH3c(bin3.07),qPH7b and qEH7b(bin7.04).The results illustrated that plant height and ear height perhaps was controled by some common genes.2.HL mapping results of maize plant height and ear height16 HL for plant height and 17 HL of ear height were identified in the test population SSSL×Z58 at the two sites in two years.Thereinto,6 HL for plant height including h1PH3b,h1PH4,h1PH7b,h1PH10,h1PH1a and h1PH6b were detected simultaneously in different environments,and 6 HL for ear height including h1EH7a,h1EH4a,h1EH1c,h1EH7b,hlEH9c and h1EH6b were detected simultaneously in different environments.A total of 16 HL for plant height and 16 HL for ear height were identified in two sites in two years using the test population,which derived from SSSL×9058.Out of them,4 HL for plant height including h2PH8b,h2PH6a,h2PH9b and h2PH1b and 6 HL ear height including h2EH1a,h2EH8b,h2EH3b,h2EH6a,h2EHlc,h2EH1b were detected simultanesouly at different environments.height as well as h3EH8 and h3EH9 for ear height were detected in diffident environments.3.The genetic bases of Heterosis for plant height and ear heightThe HL for plant height,h1PH3b,h1PH4,h1PH7b and h1PH1a detected in the test population of SSSLxZ58 displayed dominant effect,while h1PH6b showed over-dominant effect.The HL for plant height,h2PH8b and h2PH1b detected in the test population SSSL×9058 displayed dominant effect,while h2PH3c showed over-dominant effect.The HL h3PH8b identified in the test population SSSL×T7296 showed dominant effect.Similarly,the PH for ear height,hlEHlc and h1EH7b displayed dominant effect,while hlEH6b and h1EH9c displayed over-dominant effect,which identified in the test population of SSSLxZ58.While the HL for plant height,h2EH1c,showed dominant effect,h2EH3b and h2EH8b for ear height showed over-dominant effect,which identified in the test population SSSL x9058.Consequently,the heterosis of plant height and ear height was derived with both dominant effect and over-dominant effect.Furthermore,the heterosis loci of plant height and ear height detected through the test populations derived from SSSL and Z58,9058 and/or T7296 were diffident from one another,the results illustrated that heterosis was induced by interactions between allele being from loxp site in particular combination.