Kentucky bluegrass (Poa pratensis L.) is widely used because of its adaptation to recreational spaces in the Intermountain West and elsewhere. It is considered salt sensitive and therefore is a good candidate for breeding improvement for this trait. However, improvement in Kentucky bluegrass is difficult because of apomictic reproduction and dosage effects from high polyploidy. The objective of this study was to evaluate salinity tolerance of Kentucky bluegrass hybrids and their parental lines and identify those with above mid-parent trait values for salt tolerance to identify lines for future breeding. Fifteen hybrid progeny from five paired crosses were previously identified, their apomictic offtype characterized with flow cytometry, and their turf quality (TQ) and electrolyte leakage (EL) traits measured over time and under salt treatment. There was significant variation in salinity tolerance among the different parents and hybrids, with most hybrids showing trait values between the two parents. The salt-tolerant parents PI440603 and PI371768 produced hybrids with greater than mid-parent tolerance when crossed with elite Kentucky bluegrass cultivars. Seven hybrids [(‘Washington’ × PI440603)-3 and -5, (PI499557 × PI440603)-1 and -2, (PI578827 × PI371768)-1 and -2, and (‘North Star’ × PI371768)-1] had above mid-parent averages, significantly better TQ and EL than their respective salt-sensitive parent, or the smallest change in TQ or EL values between control and salt-treated plants.

中文翻译：

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肯塔基蓝草杂种耐盐性状的遗传

肯塔基早熟禾（Poa pratensis）L.) 因其适用于 Intermountain West 和其他地方的休闲空间而被广泛使用。它被认为是盐敏感的，因此是该性状育种改良的良好候选者。然而，由于高多倍体的无融合生殖繁殖和剂量效应，肯塔基兰草的改良很困难。本研究的目的是评估肯塔基早熟禾杂种及其亲本系的耐盐性，并确定具有高于中亲本耐盐性状值的那些，以确定用于未来育种的品系。先前已经鉴定了来自五个配对杂交的 15 个杂交后代，它们的无融合生殖异型以流式细胞术为特征，并且随着时间的推移和盐处理测量了它们的草皮质量 (TQ) 和电解质泄漏 (EL) 特性。不同亲本和杂种之间耐盐性存在显着差异，大多数杂种在两个亲本之间表现出性状值。耐盐亲本 PI440603 和 PI371768 与优良的肯塔基早熟禾品种杂交时产生的杂种耐受性高于中亲本。七个杂种 [('Washington' × PI440603)-3 和 -5，(PI499557 × PI440603)-1 和 -2，(PI578827 × PI371768)-1 和 -2，和 ('北极星' × PI371768)-1]具有高于中间亲本平均值，TQ 和 EL 显着优于其各自的盐敏感亲本，或者对照和盐处理植物之间的 TQ 或 EL 值变化最小。耐盐亲本 PI440603 和 PI371768 与优良的肯塔基早熟禾品种杂交时产生的杂种耐受性高于中亲本。七个杂种 [('Washington' × PI440603)-3 和 -5，(PI499557 × PI440603)-1 和 -2，(PI578827 × PI371768)-1 和 -2，和 ('北极星' × PI371768)-1]具有高于中间亲本平均值，TQ 和 EL 显着优于其各自的盐敏感亲本，或者对照和盐处理植物之间的 TQ 或 EL 值变化最小。耐盐亲本 PI440603 和 PI371768 与优良的肯塔基早熟禾品种杂交时产生的杂种耐受性高于中亲本。七个杂种 [('Washington' × PI440603)-3 和 -5，(PI499557 × PI440603)-1 和 -2，(PI578827 × PI371768)-1 和 -2，和 ('北极星' × PI371768)-1]具有高于中间亲本平均值，TQ 和 EL 显着优于其各自的盐敏感亲本，或者对照和盐处理植物之间的 TQ 或 EL 值变化最小。