Inheritance of tolerance to low soil ph in barley

Hereditas 88:IOI-I05 (1978) Inheritance of tolerance to low soil ph in barley OLAV SQ)LE and SIGURD ADERSE Department of Crop Husbandry and Plant Breeding, Royal Veterinary and Agricultural University, Copenhagen, Denmark SQLE, 0. and ADERSE, S. 1978. Inheritance of tolerance to low soil ph in barley. - Hereditas 88: 101-105. Lund, Sweden. ISS 0018-0661. Received ovember 30, 1977 Progenies after crosses between 3 ph tolerant and 2 non-tolerant barley varieties were evaluated in field experiments laid out on acid soil (ph 4.6, KCI). he results showed that the tolerance to high soil acidity is controlled by a single dominant gene, Pht. he gene is located in chromosome 4, and is linked to the gene K (hooded barley). he recombination value is approximately 25 units. Olav Stden, Department of Crop Husbandry and Plant Breeding, horvaldsensvejlo, DK - 1871 Copenhagen, Denmark Although barley grows best on soils with fairly varieties see S~LE (1965, 1972). he F,-hybrids high ph, varieties which tolerate lower soil ph of all crosses were grown in greenhouse and have been found (VA DOBBE 1959; GALJHIER selfed for the production of the F,-generation. he 1958; VA ESSE and DAUMA 1962; CHIASSO F,-population called B was composed of prog- 1964; SOLE 1965). enies from crosses between Scots Bere and 14 Fou et al. (1965, 1967), MACLEA and CHLASSO lines carrying various marker genes. he lines (1966), MACLEOD and JACKSO (1967) and REID et were obtained from Arne Hagberg, Swedish Seed al. (1969) showed that some barley varieties are Association, Svalov. not only tolerant to low soil ph, but more he F,-population A was tested in 2 field specifically to high concentrations of aluminium in experiments performed on a medium light clay low ph soils. REID (1970) in his work with winter soil with ph of 4.6 (KCI). he experiments nos. I barley found the Al tolerance in the varieties and 2 were randomized block design with 5 and 6 Dayton and Smooth Awn 86 to be controlled by a replications, respectively. Each plot, bordered by single dominant gene. spring-wheat plants, comprised 50 plants equally his report presents data on the inheritance of a distributed in 5 rows 2 m long and 25 cm apart. gene for tolerance to high soil acidity and its location in the barley genome. Materials and methods F,-populations. - During the winters of 1973/74 and 1974/75 diallel crosses were made between the three ph-tolerant barley varieties Scots Bere, Hordeum macrolepis, Sigurdkorn and the two non-tolerant varieties Bonus and Fero. his rnaterial was called population A. For details of the Experiment I. -he F,-seeds of (A) were planted in April 1974. he material was harvested when the plants in a cross or a parental line had developed to the heading stage. he plants were cut at ground level, and oven-dried at 100 C fai 21 hours, after which the dry weight of each plant was recorded. Experiment 2. - Seeds of (A) were again planted in April 1976. In this experiment the plants were not harvested, but classified for tolerance in the field.

~~ 102 0. S0LE AD S. ADERSE Hereditas 88 (1978) able I. Dry-matter yield per plant (g) in a 5 x 5 diallel cross of barley Means are average of approximately 300 F,-plants Hr I at i ve frrquenc,y 1 0.34.. 11.32 -, 33 75 262 276 592 33 16.1 17.0 12.4 12.1 19.1 75 11.6 13.4 12.9 15.0 262 5.4 5.3 13.5 276 3.4 12.3 592 15.5 IK able 2. Segregation in F,-populations after crosses between three ph-tolerant and two ph-nontolerant barley varieties Expected ratio 3: I. =tolerant, = non-tolerant Cross Obs. xz otal P no. of x2 values plants H. rnacrolepis H. rnacrolepis Sigurdkorn Sigurdkorn S. Bere S. Bere I P z x z P 220 74 294 215 77 292 201 80 281 206 80 286 22 I 66 287 209 77 286 0.001 0.003 0.004 0.95 to0.975 0.073 0.219 0.292 0.50 to 0.75 0.45 I 1.353 1.804 0.10 to0.25 0.337 1.010 1.347 0.10 to0.25 0.128 0.461 0.589 0.25 to 0.50 0.141 0.423 0.564 0.25 to 0.50 0 262 x 276!I.!I8 0. Oh (I. 04 0 0 262 A 276 0 2 4 h 8 10 I? I$ I I.in t dry-we L gti t in granmirs Fig. I. Plant dry-weight distribution of parents and Fz after a cross of 2 ph-non-tolerant varieties. he plants were grown in soil with ph of 4.6. all and vigorous plants were classified to be of the tolerant type. Short and weak plants (often with necrotic spots on the leaves) were classified as susceptible to low soil ph. Experiment 3. - F,-seeds of (B) were planted in April 1974. he distance between individual plants was lox 10 cm. In July the plants were pulled from the ground and sorted into 4 groups: (I) Well developed plants with marker genes. (2) Well developed plants without marker genes. (3) Small plants with marker genes. (4) Small plants without marker genes. Experiment 4. - In 1976 seeds of (B) were planted individually in glass test tubes (I00 mm long, diam. 28 mm). he tubes were filled with the same soil as described above. When 314 of the plants had developed roots down to the bottom of the tube, classification of the material was undertaken. Plants which had filled the tube with roots were classified as ph-tolerant and those with weak rootdevelopment as ph-susceptible. After this classification the material was then transplanted to pots and grown until maturity when sorting for marker genes took place.

Hereditus 88 (1978) OLERACE O p~ I BARLEY 103 Relative f rcquency 0.14 h (1 2 4 8 10 12 14 16 18 20 22 24 26 28 1 1 t dry-wc ight i ii grdium s Fig. 2. Plant dry-weight distribution of parents and F, after a cross of 2 ph-tolerant varieties. he plants were grown in soil with ph of 4.6. Results Experiment I. he non-tolerant varieties Bonus (KVL 262) and Fero (KVL 276) had much lower dry-matter yield per plant than the three tolerant varieties Hordeum macrolepis (KVL 33), Sigurdkorn (KVL 75) and Scots Bere (KVL 592) cable I). However, the average F,-plant weight covers wide variation as is illustrated for each of the three types of crosses: non-tolerant x non-tolerant (Fig. l), tolerant x tolerant (Fig. 2) and non-tolerant x tolerant (Fig. 3). he variation of the F,-population of the nontolerant varieties Fero (Fig. I) and of the tolerant varieties H. macrolepis X Scots Bere (Fig. 2) resemble the variation of the parents although the data suggest a wider variation of the F,-population. In the non-tolerant x tolerant cross, exemplified by the cross between Bonus and Scots Bere (Fig. 3), the variation of the F2- population is similar to that of the tolerant parent. Also in this type of cross, the F,-generation has a wider variation than either of the parents. Analysis of variance confirms that the entries (parent and crosses) possess significantly (P. 0.001) different tolerance to low soil acidity. Results from experiment 2 carried out in 1976 when the plants were classified in the field are presented in able 2. It will be noticed from the table that there is a lack of non-tolerant plants when these are classified for a 3:l segregation. his is most pronounced in the crosses of Sigurdkorn and Sigurdkorn. Probably this phenomenon is related to the wilting of nontolerant plants in the early germinating phase. he best fit to the 3:l ratio was found in the crosses H. macrolepis and H. macrolepis. Although the observed data from the crosses of S. Bere and S. Bere do not fit the expected ratio too well, the P-values from the chi-square test, ranging from 0.20 to 0.50, do not indicate that the hypothesis of a 3:l ratio necessarily should be rejected. A poor fit to the 3:l segregation (P =O. 104.20) was found in crosses of Sigurdkorn and Sigurdkorn cable 2). In the F2-material of group B, grown in the field in 1974 (experiment 3), linkage between the gene for ph-tolerance and the gene K (hooded) in chromosome 4 was observed. he recombination value between the two genes was estimated to be 18.7 k4.4 in the field experiments Fable 3). When measured on the material grown in the greenhouse (experiment4) the recombination value was found to be higher, 25 k 1.7. Since the last crossing-over value is based on the largest number of plants with the smallest variation cable 3), the value of 25.7 is judged to be the most accurate.

104 0 S0LF AD \ ADI-RSF 0.!f,L, 5Y? 0 Ih? A 592 0 2 5 h 8 I0 Ii I: If, I8 20 LL?i Lh 28 30 l'i.iril ilry-w~~ighr in grxm;es Fig. 3. Plant dry-weight distribution of parents and F, after a cross of a ph-non-tolerant and a ph-tolerant variety. he plants were grown in soil with ph of 4.6 o linkage was observed between the gene for ph-tolerance and the gene int"s (intermediate for 2rd, V.S. 6rd.) or the gene ert'':' ierectoid). Discussion and conclusion Uniform field plots with low soil acidity are difficult to obtain and variation in the yield of single plants is often great. his may be due to the fact that ph expresses a logaritmic function and therefore even small changes in ph values may drastically influence the availability or excess of elements in the soil. olerant and non-tolerant varieties, like those listed in able 1, therefore tend to have equal single plant variation (Fig. 3) even though their means are significantly different (able I). he crosses between tolerant and nontolerant varieties indicate that tolerance is a dominant character since the distribution of the F,-plants in these crosses was rather similar to that of the tolerant parent. he visual classification of the F,-material in able 2 took into account not only the general appearance of the plants but also necrotic spots which are fairly common on the leaves of nontolerant plants. Still, it was sometimes difficult to decide which tolerance group an F,-plant belonged to. Despite these difficulties the data

Hereditas 88 (1978) OLERACEO PH I BARLEY 105 able 3. Linkage between ph-tolerance in the variety Scots Bere and marker genes in chromosome 4 Place of Marker xz* xpb XZAB Recombination umber experiment gene of plants % SE Field K 1.4 0.9 37 18.7 4.4 463 Greenhouse K 0.7 0.2 127 25.7 1.7 2311 Greenhouse intcs 6.0 4.2 0.2 free Greenhouse ertisj 0.2 2.8 2.9 free from the present crosses showed a good tit to a 3:l segregation. From earlier work with this material (SBLE 1972) and from the present results we therefore conclude that the tolerance to low soil acidity in the varieties tested is controlled by a simple mode of inheritance most probably by a single dominant gene. he gene, designated Pht, was located about 25 units from the gene K (hooded spike) in chromosome 4. Since this material was not tested specifically for tolerance to Al-toxicity, it is not possible to judge whether the present gene is identical to the ALP-gene found by REID (1970). Acknowledgment. - he authors wish to thank Dr. M. H. Poulsen and Dr. S.. Mishra for criticism of the manuscript. Literature cited CHIASSO,. C. 1964. Effect of, P. Ca, and Mg treatments on yield of barley varieties grown on acid soils. -Can. J. Plant Sri. 44:525-530 DOBBE, W. H. VA 1959. A testing method to determine the susceptibility of spring barley varieties to soil acidity. -Field Crop Abstr. 12: 187-188 ESSE, A. VA and DAUMA. G. 1962. olerance to acid soil conditions in barley. - Euphytica 11:282-286 FOY, C. D., ARMIGER, W. H., BRICCLE, L. W. and REID, D. A. 1%5. Differential aluminum tolerance of wheat and barley varieties in acid soils. -Agrun. J. 57:413417 FOY. C. D., FLEMIG, A. L., BURS, G. R. and ARMIGER, W. H. 1%7. Characterization of differential aluminum tolerance among varieties of wheat and barley. - Soil Sci. Soc. Am. Proc. 31 :5 13-52 I GAUHIER, F. M. 1958. olerance of barley varieties to soil acidity. -Cereal ews3:12 MACLEA, A. A. and CHIASSO,. C. 1966. Differential performance of two barley varieties to varying aluminum concentration. -Can. J. Soil Sci. 46: 147-153 MACLOD, L. B. and JACKSO, L. P. 1967. Aluminum tolerance of two barley varieties in nutrient solution, peat, and soil culture. -Agrun. J. 59r359-363 REID, D. A. 1970. Genetic control of reaction to aluminum in winter barley. - In Barley Genetics 11 (Ed. R. A. ILA), Proc. 2 Int. Barley Genet. Symp., Washington State Univ. Press, p. 409413 REID, D. A,, FLEMIG, A. L. and FOY, C. D. 1971. A method for determining aluminum response of barley in nutrient solution in comparison to response in al-toxic soil. -Agron. J. 63: ca0403 SOLE, 0. 1965. Investigations on the tolerance of barley varieties to high hydrogen-ion concentration in soil. -K. Vet.- og Landbohgjsk. Arsskr., p. 81-107 SBLE, 0. 1973. Breeding for ph tolerance in barley. - K. Vet.- og Landbohgjsk. hsskr., p. 1-13