Evaluation Of T. Aestivum Cv. Chinese Spring-L. Elongatum Disomic Addition And Substitution Lines And Chinese Endemic Wheat For Aluminum Tolerance

Acid soils, with a pH 5.50 or lower, distributed extensively around the world's land. Aluminum toxicity is one of the limiting factors for crop production in the acidic soils. There are some main acid soil types, including red soils, yellow soils, humid-thermo ferralitic and lateritic red earths. In recent years, acid deposition and poor tillage have accelerated the soil acidification. The aluminum toxicity in acidic soils has become one of the seriously global agricultural puzzles.For comparing the aluminum tolerance of wheat lines with different Lophopyrum elongatum chromosomes as well as Chinese endemic wheats and found potential new sources of aluminum tolerance,27 T. aestivum cv. Chinese Spring-L. elongatum disomic addition and substitution lines and 28 Chinese endemic wheats were tested for aluminum tolerance by using hydroponic screening. The Chinese endemic wheats werte further subjected to SSR analyses for studying the association between the genetic dissimilarity and aluminum tolerance. The main results were as follows:1. Aluminum tolerance of T. aestivum cv. Chinese Spring-L. elongatum disomic addition and substitution lines Significant difference on aluminum tolerance was observed in 27 T. aestivum cv. Chinese Spring-L. elongatum disomic addition and substitution lines, of which, the root regenerate length (RRL) of disomic additional line 2E (DA2E) was significant different lower than that of Chinese Spring (CS), while no significant different was observed in aluminum tolerance index (RTI) between DA2E and CS in all aluminum concentrations. The RRL of DA4E was almost no significant different with that of CS, but the RTI was significant different lower than that of Chinese Spring. Based on RRL and RTI, the aluminum tolerance of the remaining five disomic addition lines were very similar to CS.The RRL of substitution lines DS1E/1A in 0μM Al3+, DS4E/4D in all aluminum stress were respectively significant higher or lower than that of CS, leading to the RTI of them were significant lower than that of CS. Though the RRLs of substitution line DS3E/3B in all aluminum stress were respectively significant lower than that of CS, only the RTI in pH4.50+200μM Al3+ was lower than that of CS. Compared with CS, the aluminum of DS5E/5B and DS7E/7A in pH4.50+200μM Al3+ were worse than it. The RRLs of DS6E/6A and DS6E/6B without aluminum and DS6E/6D in pH4.50+200μM Al3+ were respectively lower than that of CS, while their RTIs without significant difference, suggesting that the aluminum tolerance of them were very similar. The RRL of DS1E/1B in all aluminum stress were respectively the same as those of CS, however, the RTI in pH4.50+200μM Al3+ were lower than that of CS.2. Aluminum tolerance among Chinese endemic wheatsThe aluminum tolerance of three types of Chinese endemic wheats were not the same, some wheat lines showed the same or even much better aluminum tolerance as/than CS.Among all the three types of Chinese endemic wheats, Yunnan hulled wheats have shown much better aluminum tolerance than Xinjiang rice wheat and Tibet semi-wild wheats. It was found that all of Yunnan hulled wheat lines showed similar aluminum tolerance as CS in pH4.00+120μM Al3+. Distinguishly, some Yunnan hulled wheat lines showed much better aluminum tolerance than CS even in pH4.00+240μM Al3+ and pH4.00+360μM Al3+, respectively.Xinjiang rice wheat line As360 is one of the best aluminum tolerance wheat lines in all the tested Chinese endemic wheats. Surprisingly, the aluminum tolerance of the remaining Xinjiang rice wheats was poorer than CS.Most of Tibet semi-wild wheats showed the same aluminum tolerance as CS when aluminum concentration below 120μM Al3+3. The association between genetic dissimilarity and aluminum tolerance in Chinese endemic wheatsBased on the polymorphic SSR data clustering results, all Chinese endemic wheats could divide into two groups. The one group contained Yunnan hulled wheats, Tibet semi-wild wheats and CS, while the remaining group contained seven lines of Xinjiang rice wheat.The genetic distance between aluminum tolerance Xinjiang rice wheat line As360 and CS was very far, suggesting that the aluminum tolerance gene(s) of As360 probably not the same as that of CS.All Yunnan hulled wheats showed the same aluminum tolerance as CS when aluminum below 120μM Al3+. Distinguishly, some Yunnan hulled wheats showed the same or much better aluminum tolerance as/than CS. Combined with clustering data, it suggested that the aluminum tolerance genes of Yunnan hulled wheats may be different from CS.Some Tibet semi-wild lines showed the same aluminum tolerance as CS when aluminum concentration below 120μM Al3+ and showed very near distance with CS, suggesting that the aluminum tolerance genes of them were probably very similar or the same.