Euphytica 35 (1986) 677-685

THE DEGREE OF SIMILARITY OF BACKCROSS LINES OF TRITICUM AESTIVUM CULTIVARS MANITOU AND NEEPAWA W ITH AEGILOPS

SPELTOIDES ACCESSIONS AS DONORS

A. C. ZEVEN and J. WANINGE

Department of Plant Breeding (IvP), Agricultural University, P.O. Box 386,670O AJ Wageningen, the Netherlands

Received 13 January 1986

INDEX WORDS

Triricum aestivum, bread wheat, backcross lines, similarity Aegilops speltoides, inhibitor gene.

S U M M A R Y

The degree of similarity of a BC line with its recurrent parent is not related to the presence of expressions for morphological characters originating from the donor like purple coleoptile, purple anther and waxy leaf. BC lines derived from one donor do not resemble each other more than they do other BC lines. The absence of characters conditioned by dominant or co-dominant genes may be caused by the presence of inhibitor genes.

INTRODUCTION

Genes (Lr) for leaf rust (Puccinia recondita ROB. ex DESM.) resistance were introduced by backcrossing into the genetic background of the bread wheat (Triticum aestivum L. em. THELL.) cultivars Manitou and Neepawa. As source of Lr genes KNOTT& DVOR- AK (1981) used the Aegilops speltoides TAUSCH. accessions 0, 2, E, F and H of the University of Saskatchewan, Saskatoon, Canada. The number of backcrosses was 4 or 5 (Table 1). Agronomic and quality characteristics of these backcross (BC) lines and their recurrent parents were studied by the breeders. They concluded that most backcross lines were, with regard to characters other than leaf rust resistance, less promising than their recurrent parent. Apparently donor genes linked to Lr genes or still being present had a deleterious effect (KNOTT & DVORAK, 1981; KNOTT, 1984). Maybe the unbalance of co-adapted gene complexes is another cause of their poor performance (ZEVEN, 1984). Furthermore, some backcross lines are possibly deficient for some wheat chromosome segments while their absence is not compensated for by genes from Ae. speltoides (MOONEN & ZEVEN, 198.5).

KNOTT & DVORAK (198 1) described the presence of Ae. speltoides characters in some of the BC lines. These have been listed in Table 1. Data on glutenin from MOONEN & ZEVEN (1985) and own observations of field grown plants were added (Table 1). Some BC lines have many Ae. speltoides characters, others have a few, while three BC lines possess at least one Ae. speltoides chromosome segment carrying an Lr gene

677

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Table 1. Breeding history and presence of Ae. speltoides characters in the backcross lines.

Recurrent Donor Backcross parent parent l ines’

Manitou E Mit-E-l l-3

Neepawa F

Mit-E-11-8 Mit-E-l l-14 Np-F-7-3 Np-F-7- 10

Np-F-7- 12

H NP-H-~-~~

Np-H-9- 10

0 N~-O-1-14~

2 Np-2-9-2

Ae. speltoides and other deviat ing characters’

low 1000 grain weight, little taller, low baking quality, absence of glutenin subunits 5 and 9, presence of glutenin subunits Sl and S2,1ater*, purple coleoptile* - little taller - low yield, shorter, low 1000 grain weight, slightly later, low bak- ing quality, absence of glutenin subunits 3 and 10 low yield, shorter, slightly later, low baking quality, absence of glutenin subunits 3 and 10, purple anther* shorter, segregat ing for waxiness, for purple anther, and for pur- ple coleoptile* waxyless, purple anthers, shorter, low 1000 grain weight, lodging* purple coleoptile*, purple culm* very low yield, shorter, early purple coleoptile*, purple culm*, purple anther

’ The number of backcrosses was 5 except for Np-0-1-14 for which it was 4. ‘Based on KNOTT & DVORAK (1981) for morphological data, M~~NEN & ZEVEN (1985) for glutenin data, and own* observat ion. 3 See text for recoding into Np-H-9-6A, Np-H-9-6BG, and Np-H-9-6BK. 4 See text for recoding into Np-0-l-14A and Np-0-I-14B.

condit ioning resistance to one or more races of Puccinia recondita ROB. ex DESM. caus- ing leaf rust.

Our aim of investigation was to study the degree of resemblance of the BC lines with their recurrent parent and to establish whether BC lines with many Ae. speltoides characters (see above) deviate more from their recurrent parent than those with a few or without any conspicuous donor characters.

Preliminary data were provided by HOVERS (1983). She based her conclusions on her data on time of flowering, number of ears per plant, plant length, ear length, flag leaf b lade length, number of spikelets per ear, number of grains per ear, 1000 grain weight, gliadin pattern and purothionin pattern. HOVERS (1983) concluded: 1. M it-E-l l-3 differs greatly from ‘Man itou’, 2. M it-E-l l-8 resembles ‘Man itou’, 3. M it-E-11-14 is intermediate between its two sister BC lines, 4. Np-F-7-3, Np-F-7-I’O , Np-H-9-6A and Np-2-9-2 resemble ‘Neepawa’, 5. Np-H-9-6BK deviates greatly from ‘Neepawa’, 6. Np-F-7-12, Np-H-9-6BG, Np-H-9-10, Np-0-l-14A and NP-0-114B differ to some

extent from ‘Neepawa’.

MATERIALS AND METHODS

The ten BC lines presented in Table 1 were developed by KNOTT & DVORAK (1981). As recurrent parent eigher ‘Man itou’ or ‘Neepawa’ was used. The breeding history

678 Euphyiica 35 (1986)

SIMILARITY OF BC LINES AND RECURRENT PARENT

of the BC lines is presented in Table 1. Nine lines were BC.5 lines and only one, Np-O-l- 14 was a BC4. ‘Man itou’ and ‘Neepawa’ have a ‘Thatcher’ background. If no selection was carried out during the backcross programme to breed these recurrent parents the percentage Thatcher genome in ‘Man itou’ would have been 98.6 and that in ‘Nee- pawa’ 55.7. However, both varieties carry Ne2 (APLTAUEROVA, 1969; MCINTOSH, pers. comm., 1980) while ‘Thatcher’ is a non-carrier (HERMSEN, 1963). HAWTHORN (1981, 1984) indicated close l inkage between SrTt2 (stem rust resistance), Lr13 (leaf rust resis- tance), Lr23 and Ne2. Owing to selection for these resistance genes Ne2 was ‘dragged into’, ‘Man itou’ and ‘Neepawa’, i.e. the percentages ‘Thatcher’ genome are smaller than indicated above.

According to KNOTT & DVORAK (1981) Np-H-9-6 was impure for waxy leaf. This was also observed by us. W e also noticed impureness for coleoptile colour and anther colour. Those with green coleoptiles were recorded Np-H-9-6A, and those with purple coleoptiles Np-H-9-6B. HOVERS (1983) observed that the latter type consisted of nor- ma l-size plants and a few rather small plants. These were recoded Np-H-9-6BG and Np-H-9-6BK (small plants). The average length of the latter was 53.9 cm, while the Np-9-6BG plants had a mean length of 99.4 cm. The Np-H-9-6A plants had a mean length of 101.6 cm. On ly the length of the Np-H-9-6BK plants differed significantly at P = 0.01 from the mean length (100.0 cm) of ‘Neepawa’. W e did not study the origin of these different types (HOVERS, 1983). The Np-H-9-6BG plants were waxy and had yellow anthers, and the Np-H-9-6BK were waxy and had purple anthers.

Np-O- 1 - 14 also consisted of two types viz. Np-O- I- 14A with waxy leaves, and Np-O- 1-14B without waxy leaves. The origin of this differences was not studied. In addit ion the scoring for coleoptile colour, waxiness of leaves, anther colour, lodging, culm col- our at the time of ripening, and glutenin patterns the relative amounts of cereal isolec- tins CL(A), and CL(D) were determined by W . J. Peumans (unpublished, 1984). The method used is described by PEUMANS et al. (1982), STINISSEN et al. (1983), and ZEVEN & PEUMANS (in prep.). Np-0-1-14 was accidentally om itted by us.

Yield data were obtained in 1982, 1983 and 1984 by growing plants in a randomized block design with three replicates. The size of each plot was 12 m* (10 rows 8 m long). The experiments were located in the IvP experimental area. In 1984 this experiment was also planted on the experimental area of the APM farm, F levopolder, the Nether- lands. In 1984 at both sites the degree of lodging was scored. After harvest the grain weight per plot was taken. In 1983 and 1984 the 1000 grain weight was measured and the number of grains per m2 was calculated per plot. Percentage grain nitrogen (%N) was obtained after Kjeldahl with a Technicon auto-analyzer. For 1982 for each line only pooled seed harvested on the 3 plots was available.

Differences for yield per plot, yield components, %N and degree of lodging were analysed with analyses of variance. ‘Man itou’ and its BC lines, and ‘Neepawa’ and its BC lines were analysed separately.

The data presented in Table 3 were used to generate dendrograms and scatter dia- grams. Dendrograms and scatter diagrams were obtained with the clustering tech- niques available in the computer programme PATIMA (developed by G . Stafleu, Computer Center, Agricultural University, Wagen ingen). For generat ing dendro- grams the data were transformed by STAND and NORM. STAND standardizes the data within each column of Table 3 i.e. it sets the mean at 0 and the standard deviation

Euphytica 35 (1986) 679

A. C. ZEVEN AND J. WANINGE

at 1 by calculating y = (x-mean)/s.d. Alternatively NORM normalizes the data within each column, i.e. it sets the maximum at 1 by calculating y = (x/max) in which max is the maximum value within a column. As dissimilarity criterion MNSQ was used. It computes the averaged squared Eucl idean distance between two lines: MNSQ = (xi - Yi)‘/N, were xi is some observation on one line and yi is the same observation on the other line. Summation is over all N attributes. Further, the method WARD was used. The smaller the distance between two lines the more similar these lines are.

For generat ing the principal component analyses (PCA) the similarity criterions CORR and CORA were used. CORR is a similarity criterion comput ing the correla- tion coefficient (Pearson product moment) between two objects. CORA = ABS (CORR).

RESULTS AND DISCUSSION

Pigmentation and waxiness of leaves. Data on deviating colour of the coleoptile, anther, and culm at the time of r ipening are presented in Table 1. The differences among NP-H-9-6A, Np-H-9-6BG and Np-H-9-6BK have already been described. When one of the above organs is p igmented the other two are also coloured in most BC lines, but this was not true for Np-H-9-6BG (purple coleoptile, yellow anther). Probably no basic gene for anthocyanin production is involved in this BC line. The absence of the pigment in the anthers of this BC line could also be condit ioned by a suppressor gene. As ‘Neepawa’ has yellow anthers too this suppressor gene could come from this variety. ‘Man itou’ and ‘Neepawa’ are both waxy. Wax production is induced by gene W 1. Waxlessness is condit ioned by the genotype wlwl, or by a dominant suppres- sor gene. In both cases this gene must derive from Ae. speltoides. Suppressor genes have been identified in bread wheat, Triticum dicoccoides , Aegilops squarrosa (McIN- TOSH, 1983 for review) and Ae. triuncialis (TSUJIMOTO & TSUNEWAKI, 1985). It is also possible that wax was present but not observed as described by JOHNSON et al. (1983).

HMWgZutenin. High Mo lecular W e ight (HMW) glutenin patterns of the lines showed that except for Np-F-7-10, Np-F-7-12 and M it-E-l l-3 all l ines had an identical pattern (MOONEN & ZEVEN, 1985) viz. subunits 2 *, 3 + 10, 5 and 8 (according to the code Of MOONEN et al., 1983).

Np-F-7-10 and Np-F-7-12 m iss subunits 3 + 10 which are coded by one gene G lu- D 1 d. This gene is located on the long arm of chromosome 1D (1 DL) (PAYNE & LAW- RENCE, 1983). It is possible that there is a deletion on IDL (MOONEN & ZEVEN, 1985) or that the expression of this gene is completely suppressed by an inhibitor gene. The sister line Np-F-7-3 possesses gene G lu-Dld.

M it-E-l l-3 possesses two subunits named Sl and S2 which do not occur in the recurrent parent and probably derive from Ae. speltoides E. This BC line m isses the subunits 5 + 9 which are condit ioned by the gene G lu-Blc. This gene is located on the long arm of chromosome 1B (IBL) (PAYNE et al., 1983). Maybe there is a deletion on 1BL. Our G lu-Blc is competely suppressed by an inhibitor gene. It is not known whether the gene(s) for Sl and S2 replace(s) G lu-BI.

Wheat isolectins. In Table 2 the relative amounts of wheat isolectins CL(A), CL(B)

680 Euphytica 35 (1986)

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Table 2. Relative quantities of wheat isolectins (in %) and their relation of CL(A) (W. J. Peumans, 1984, unpublished).

Manitou Mit-E-l l-3 Mit-E-11-8 Mit-E-11-14

Neepawa Np-F-7-3 Np-F-7-10 Np-F-7-12 Np-H-9-6 Np-H-9-10

*Np-F-7-10 *Np-F-7-12

%CW) %CL(B) %CW’)

50.2 12.0 37.8 52.1 12.4 35.6 52.0 12.1 35.9 52.1 12.4 35.6

49.8 13.8 36.4 50.6 14.7 34.7 82.1 10.5 7.4 82.2 11.2 6.6 46.3 15.9 37.8 54.9 8.4 36.7

49.8 6.4 4.5 49.8 6.8 4.0

CL(B)/ CL(D)/ CL(A) CL(A)

0.24 0.75 0.24 0.68 0.23 0.69 0.24 0.77

0.28 0.73 0.15 0.69 0.13 0.09 0.14 0.08 0.34 0.82 0.15 0.67

* Figures based on CL(A) of Neepawa; see text.

and CL(D) and their relation to CL(A) are given. Most lines have similar relative quantities as their recurrent parent. Np-F-7-10 and Np-F-7-12 have low percentages for CL(B) and CL(D). In the densitogram the peaksize for CL(A) is about the same as that of the other lines. Therefore we have ‘corrected’ the figures for CL(A), CL(B) and CL(D) by taking the CL(A) value of ‘Neepawa’ as reference, and keeping the same ratios between the three isolectins. The percentages CL(B) and CL(D) become still lower, but of course they do not become zero (Table 2). The behaviour of these NILS is difficult to explain. One would expect that the genes coding CL(B) and CL(D) are either present or absent. If absent, there would be no production of CL(B) and CL(D) and the figures would be 100% CL(A), 0% CL(B) and 0% CL(D). If present, f igures similar to those of the other lines would be expected. Peumans (pers. corn. 1984) has stated that the percentages for CL(B) and CL(D) are not zero, so some gene action is present. Therefore, at present we can only put forward two hypotheses to explain the above: 1) there is an inhibitor gene suppressing incompletely the actions of the genes coding CL(B) and CL(D); 2) on chromesomes 1B and on 1D there is more than one gene for CL(B) and for CL(D) respectively. It is suggested that both chromosomes have a deletion in such a way that at least one locus is still present. W e recall that both lines may also possess a deletion on the long arm of chromosome 1D (see glutenins). W e prefer hypothesis 1. The inhibitor gene(s) must have come from Ae. speltoides F. This problem needs further investigation.

Yield data, % grain nitrogen. Data on yield over 1982-1984, two yield components, ‘A grain nitrogen and degree of lodging are presented in Table 3. The last column gives the number of cases in which an attribute of a BC line differs significantly from the recurrent parent.

When studying the yield expressed in kg/ha we observe that the yields of the BC lines are equal to or lower than that of their recurrent parent. This was also observed

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Table 3. Average yield (kg/ha), average % grain nitrogen (%N) and average lodging degree at the IvP and at the APM in 1982 to 1984.

Line IVP

Manitou 3207 2.61 3140 25.9 12124 2.77 Mit-E-l l-3 2451* 2.87 2526 25.5 9906 3.20 Mit-E-l l-8 2951 2.75 3058 26.0 11762 2.95 Mit-E-l l-14 2861 2.72 2701 25.4 10634 2.97

Neepawa 3235 2.53 3293 29.0 11355 2.73 Np-F-7-3 3146 2.63 3104 29.4 10252 2.92 Np-F-7-10 1862* 3.20 2706 28.3 9562 3.28 Np-F-7-12 2380* 3.14 2444* 27.9 8760* 3.05 Np-H-9-6 2798 2.59 3142 28.2 11142 2.89 Np-H-9- 10 2449* 2.79 2076* 25.0* 8304* 2.90 Np-0-1-14 1631* 4.36 1696* 29.5 5749s 3.48 Np-2-9-2 2798 2.82 2606* 34.4* 7576* 3.14

1982 1983 1984

kg/baa %N kg/baa TGW(g)b number of grains/m2

%N kg/ha” TGW(g) number of grains/m2

4128 30.9 2956* 27.3* 4111 29.6 4161 30.2

4525 33.5 4317 34.0 3006* 32.5 3350* 31.5* 4508 33.4 3433’ 27.1* 2892* 35.4* 3564* 39.6*

13359 10828* 13888 13778

13507 12697 9249*

10635* 13497 12668 8169* 9000

a Not included in the clustering processes, and not used for the last column. bTGW = 1000 grain weight. ’ 1 = no lodging, 15 = severe lodging. *, **, ***significant differences between the NIL and the recurrent parent at p = 0.05,O.Ol and 0.001 respectively.

by KNOTT (1984). Apparently, the presence of genetic material from Ae. speltoides as such or in combination with that of the recurrent parent is deleterious, leading to reduced yielding ability in BC lines like M it-E-11-3, Np-F-7-10 and Np-0-1-14. In most cases the lower yield is caused by both yield components: 1000 grain weight and number of grain per m2.

It m ight be of interest to note that the 1000 grain weight of ‘Neepawa’ is higher than that of ‘Man itou’ and this fact is also observed in most of the BC lines.

Almost all BC lines had a % grain nitrogen equal to that of their recurrent parent, except for those obtained from the APM experimental area in 1984.

Most BC lines have the same degree of lodging as their recurrent parent. But M it-E- 11-S was stronger than ‘Man itou’ at the APM experimental area, while Np-F-7-3 and Np-H-9- 10 were much weaker than ‘Neepawa’.

When we add up per BC line all cases in which an attribute differs significantly from the same attribute of the recurrent parent (see Table 3) we observe: for ‘Man itou’: 1) M it-E-l l-3 differs to some extent from ‘Man itou’, 2) the two other lines resemble ‘Man itou’; for ‘Neepawa’: 1) Np-F-10, Np-F-7-12. Np-H-9-10, Np-0-1-14 and Np-2-9-2 differ from ‘Neepawa’, 2) Np-F-7-3 resembles ‘Neepawa’ to some extent, 3) Np-H-9-6 equals ‘Neepawa’.

All investigations indicated that M it-E-11-3 is quite unlike ‘Man itou’, except for the cereal isolectin data (Table 2).

682 Euphytica 35 (1986)

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APM in 1984

kg/baa DKG(g)

%N lodgingC

2.68 2.3 2.81 3.0 2.65 2.3 2.66 3.3

2.48 1.3 2.41 4.F 2.93 1.0 2.91 1.7 2.48 2.0 2.19 4.F 3.09* 1.3 2.71 1.0

3381 30.5 11085 2169 30.8 7042** 2942 30.6 9614 2833 29.4 9639

3558 3197 2333* 2536* 3269 2394* 1889* 3106*

34.2 35.3* 33.3* 33.6* 34.2 28.9* 34.5 40.2*

10404 9057 7006* 7548*** 9558 8284** 5475*** 7126***

number of grains/m*

%N lodging

2.49 2.1 2.96 3.0 2.15 2.0* 2.65 5.0*

2.48 1.0 2.57 5.0* 2.89* 1.0 3.01* 1.3 2.49 1.3 2.61* 5.0* 2.87* 1.7 2.70* 1.0

number of attributes differing significantly from the recurrent parenta

- 4 1 1

Based on data presented in Table 1 (KNOTT & DVORAK, 1981; M~~NEN & ZEVEN, 1985 and our data on pigmentation and waxiness) M it-E-11-8 did not show any con- spicuous Ae. speltoides character. Its resemblance to ‘Man itou’ is supported by HOVERS (1983) and our data (ANOVA and cluster analyses).

M it-E-11-14 also did not not show conspicuous Ae. speltoides characters (Table l), except that it was a ‘little taller’ (KNOTT & DVORAK, 1981). Its resemblance to ‘Man itou’ is supported by our ANOVA results (Table 3), but not by the results of our cluster analyses.

Np-F-7-3 resembles ‘Neepawa’ (Table 1). This is supported by HOVERS (1983) and our ANOVA results (Table 3), but not by the data on cereal isolectins or by the results after cluster analyses (dendrograms and scatter diagrams not presented here).

Np-F-7-10 has no Ae. speltoides characters. So it resembles in this respect ‘Nee- pawa’. This is supported by HOVERS (1983), but not by the data for yield, cereal isolec- tins, baking quality (KNOTT & DVORAK, 198 1) and glutenins. The last may be related, since it was observed that wheat varieties without glutenin subunits 3 and 10 have a low baking quality (MOONEN et al., 1983; M~~NEN & ZEVEN, 1985). Maybe the ab- sence of both subunits is caused by a deletion, but it is also possible that suppressor genes (from Ae. speltoides) play a part, like they may do for the cereal isolectins.

The same conclusion can be drawn for Np-F-7-12. Np-H-9-6 is a m ixture of two genotypes for coleoptile colour. HOVERS (1983) found

that the genotype with green coleoptiles (Np-H-9-6A) resembled ‘Neepawa’ more than

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A. C. ZEVEN AND J. WANINGE

the one (Np-H-9-6BG) with purple coleoptiles. As the character purple coleoptile der- ives from Ae. speltoides this observation is in accordance with expectation. MOONEN & ZEVEN (1985) did not find two glutenin patterns, so both lines had the same genotype for glutenin. KNOTT & DVORAK (1981) also found this line to segregate. Their m ixture resembled ‘Neepawa’ less than the m ixture we used. Maybe they used a m ixture with a high proport ion of Np-H-9-6BG plants, while our ‘BC line’ had more Np-H-9-6A plants.

All investigations showed that Np-H-9-10 did not resemble ‘Neepawa’. Np-O-1-14 also was a m ixture of two genotypes. HOVERS (1983) found both geno-

types to differ from ‘Neepawa’. This was supported by other investigations, except the result obtained for cereal isolectin.

According to Table 1 Np-2-9-2 has no Ae. speltoides characters. HOVERS (1983) also found that this line closely resembled ‘Neepawa’. No cereal isolectin data are available for this line (Table 2). Our investigation indicates that this line does not resemble ‘Neepawa’. This is caused by its high 1000 grain weight, low number of grains/m2 and high % grain nitrogen. These characters maybe be associated with each other.

FINALCONCLUSIONSANDRECOMMENDATIONS

The first final conclusion is that one BC line resembles its recurrent parent more than does another. This difference in resemblance is not caused by the number of back- crosses, because Np-0-1-14 which is a BC4 line behaves similar to the other (BC5) lines.

The second final conclusion is that the degree of resemblance depends on the charac- ters investigated and on the site where the material is grown. Some sites discriminate (in a certain year?) better than other sites. The third final conclusion is that the BC lines with a common Ae. speltoides parent do not group i.e. they do not resemble each other more than they resemble BC lines with other Ae. speltoides accessions as parent.

It is recommended: 1. to select for homozygous lines in BC lines that still segregate; 2. to investigate the characters of Ae. spehoides which are condit ioned by genes l inked

with the target gene; 3. to investigate whether suppressor genes play a part in inhibiting the expression

of the genes condit ioning pigmentation, waxiness, glutenin, cereal isolectin and yield componnts.

ACKNOWLEDGEMENTS

W e are most grateful to Prof. D. R. Knott, University of Saskatchewan, Saskatoon, Canada for providing us with the wheat lines, to Mr G . Heemstra for carrying out the analyses of variance, to Mr L. C. J. M . Suurs and Mr J. W . Mo lenveld for providing the %N data and to Dr W . J. Peumans for presenting us the data on the relative amounts of wheat isolectins.

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