Salinity levels that caused 25% root growth reduction ranged from as low as 2.2 to 2.5 dS [m.sup.-1] in Reveille HBG, TXKY 96-260-6 HBG, TXKY 96-260-7 HBG, Dellwood Fine KBG, and TBG to as high as 13.3 dS [m.sup.-1] in CS ST 1 KBG.
Threshold EC ranged from 1.0 to 5.0 dS NaCl [m.sup.-1], with the highest threshold EC of 5.0 observed in TBG 10-24 and TXKY 94-8-8 HBG. Values of E[C.sub.root] 25 ranged from a low of 1.9 dS [m.sup.-1] in TXKY 96-260-7 HBG to 8.5 dS [m.sup.-1] in TBG 10-24.
Although salinity levels that caused E[C.sub.root] 50 ranged from 3.9 dS [m.sup.-1] in TXKY 96-260-7 HBG to 12.1 dS [m.sup.-1] in TBG 10-24, no difference in E[C.sub.root] 50 was found between Poa species, their hybrids, or among KBG ecotypes.
The intermediate and least tolerant groups (Clusters 2 and 3, respectively) included KBG, TBG, and HBG.
Again, the intermediate and least tolerant groups (Clusters 2 and 3, respectively) included KBG, TBG, and HBG.
Optimum shoot and root growth temperature ranges have not been determined for TBG or HBG.
Current and ongoing research (Suplick and Qian, 2000) suggests that HBG may have a broader temperature adaptation than those of KBG and TBG.
II, whereas no change was seen in TBG or HBG; and (iii) there was an improvement in overall salt tolerance for all three TBG accessions, demotion of several KBG cultivars, and relatively steady ranking of HBG from Exp.