Characterization and gas exchange in accessions of Saccharum complex under salinity in the Sub-middle São Francisco, Brazil

ABSTRACT Salinity is one of the factors that most limit agricultural yield in the Brazilian semi-arid region. In this context, the present study aimed to evaluate the leaf gas exchange and biometric characteristics of accessions of the Saccharum complex subjected to salt stress. The experiment was carried out in a greenhouse, installed at Embrapa Semiárido, in Petrolina, PE, Brazil. The experimental design was in randomized blocks, with the treatments represented by 19 accessions belonging to different genera/species, being 10 accessions of Saccharum officinarum (BGCN 6, BGCN 91, BGCN 104, BGCN 127, BCGN 90, BGCN 101, BGCN 102, BGCN 118, BGCN 125 and BGCN 122), two accessions of Saccharum spp. (BGCN 87 and BGCN 89), one accession of Saccharum hybridum (BGCN 88), one accession of Saccharum robustum (BGCN 94), four accessions of Erianthus arundinaceus (BGCN 117, BGCN 119, BGCN 120 and BGCN 123) and one accession of Miscanthus spp., with three repetitions. Biometric characteristics, chlorophyll index and leaf gas exchange of the accessions were evaluated when they were subjected to irrigation with salinized water (6.0 dS m-1). E. arundinaceus accessions (BGCN 120 and BGCN 123) showed the highest photosynthetic rate, transpiration rate, plant height and leaf length, indicating greater adaptability to salt stress and could be promising in breeding programs.

摘要：盐度是制约巴西半干旱地区农业产量的关键因子之一。为此，本研究旨在探究盐胁迫下甘蔗复合群（Saccharum complex）种质的叶片气体交换特性与生物学性状。试验于巴西伯南布哥州佩特罗利纳市的Embrapa Semiárido温室中开展。试验采用随机区组设计，共设置19份不同属/种的种质作为处理材料，具体包括：10份热带甘蔗（Saccharum officinarum，编号依次为BGCN 6、BGCN 91、BGCN 104、BGCN 127、BGCN 90、BGCN 101、BGCN 102、BGCN 118、BGCN 125及BGCN 122）、2份甘蔗属未知种（Saccharum spp.，编号为BGCN 87与BGCN 89）、1份甘蔗杂交种（Saccharum hybridum，BGCN 88）、1份粗壮甘蔗（Saccharum robustum，BGCN 94）、4份斑茅（Erianthus arundinaceus，编号为BGCN 117、BGCN 119、BGCN 120及BGCN 123）以及1份芒属未知种（Miscanthus spp.），所有处理均设置3次重复。当供试种质采用盐度为6.0 dS·m⁻¹的盐化水灌溉时，对其生物学性状、叶绿素指数及叶片气体交换特性进行测定。结果显示，斑茅种质BGCN 120与BGCN 123的光合速率、蒸腾速率、株高及叶长均显著高于其他材料，表明其具备更强的盐胁迫适应性，可作为甘蔗育种项目的潜在优异种质资源。