The Second Released Variety, Xiaoyan 54

In the late 1980s, my group returned to Beijing. The winter temperature in Beijing was lower than Yangling, Shaanxi. In the new environment, new natural variations were found in Xiaoyan 6 population. Through systematical selections, Xiaoyan 54 was bred, which has two important characteristics. First, it was tolerant to drought

Fig. 43.3 After highlight treatment, the PSII light harvesting protein complexes keep intact in leaves of Xiaoyan 54, but it was damaged in Jing 411. N normal light, H high light

stress in rainfed farming. In 1998–1999, the annual rainfall declined about 40 %, only 317 mm in Guanzhong, Shaanxi province. The grain yield of Xiaoyan 54 was

3.9 t/ha, while the local variety, Shaan 354 was 1.18 t/ha. The WUE of Shaan354 was 0.25 kg/mm; however, Xiaoyan 54 was up to 0.8 kg/mm, which is 120 % of the control Shaan354 (provided by Huying Yi, Institute of Soil and Water Conservation, CAS & MWR).

Second, Xaioyan 54 is tolerant to high light stress (Fig. 43.3, Wang et al. 2000; Yu et al. 2001; Yang et al. 2006). After being stressed by high light, the PSII lightharvesting protein complexes in the leaves of “Xiaoyan 54” retain intact, but in Jing 411, they were partially damaged.

The Third Released Varieties, Xiaoyan 81 and 60

In order to meet the development of the Bohai Economic Zone, since 1990s we initiated a new breeding program, salt tolerant wheat breeding. Two new varieties, Xiaoyan 81 and Xiaoyan 60 were bred. The trail experiment showed that Xiaoyan 81 was more tolerant to salt than other varieties (Soil salt total content was almost as high as 0.3 %) in 2007. At CAS-Nanpi experimental station, Hebei province, the total soil salt content is about 0.2 %. Xiaoyan 60 grew much better than the local cultivar, Jimai 32. It also created much higher yield than the CKs in 2 years experiment on the salted land (Table 43.1).

Table 43.1 Yield performance of Xiaoyan 60 in salted field

The breeding success above mentioned made us confidence to further strengthen wild hybridization work. Ten years ago, our group repeated the original crossing work between wheat and tall wheatgrass that Li and his group did 50 years ago in Northwest Institute of Botany, CAS and used the available partial amphiploids developed in 1960–1980s to create a large number of new translocation lines. The following is some new results in the application of partial amphiploids.

The Application of Partial Amphiploids

In early 1980s, we developed some partial amphiploids, such as Xiaoyan (XY) 68, 693, 784, 7430, 7431 etc. (Fig. 43.4). Their genomes included three types which are AABBDDEE, AABBDDStSt and AABBDD + (E & St heterozygous) (Zhang et al. 1996). So, their characteristics are different. For example, in the spring of 2012, we had an opportunity to cooperate with Prof. Zakkie Pretorius, University of the Free, South Africa, to verify resistance of these partial amphiploids to stem rust Ug99. The XY68 and XY7430 showed immune, XY784 performed high resistant to Ug99. The local cultivar Fadkvz was used as control (Fig. 43.5; Table 43.2).

In addition, we also carried out the resistance identification of partial amphiploids to yellow rust, powdery mildew and tolerance to salt. So, my research group repeated the crossing work between wheat and partial amphiploids. Through the radiation treatment to their hybrid offspring, we have obtained more than 200 new translocation lines. Their cytological verification by GISH and FISH were carried out (Fig. 43.6). All of the translocation lines will be used in the multiple character identification and breeding in next stage.

Synthesis and Conclusion

Looking back 60 years work of wheat wide hybridization breeding, we believe that it has a huge potential and worth continuing, specifically in the aspect of improving wheat wide adaptability to biotic and abiotic stresses. Now climate change has been bringing various disasters on global wheat production. In China, wheat production

Fig. 43.4 The five partial amphiploids developed in 1980s at Yangling, Shaanxi

Fig. 43.5 Partial amphiploidsXY68 and XY7430 showed immune, XY784 high resistant to stem rust Ug99. The local variety Fadkvz was used as control

Table 43.2 Reaction of wheat-Th. ponticum partial amphiploids to Ug99

Fig. 43.6 New wheat-Th. ponticum translocation lines; whole arm translocation (left), small fragment translocation (middle) and insertion translocation (right)

is frequently threatened by drought, frost, logging, diseases and pests, which cause unpredictable losses. How to face these challenges?

Based on what we have experienced in the past years, it can be summarized into two strategies. The first is to develop more new germplasms with various genetic backgrounds, for example, using the alien species cross and backcross with common wheat to transfer useful traits to wheat to broaden its genetic basis. The second is to breed wide-adaptability and multi-resistant wheat varieties. The effective methods are establishing the multi-environment field trials and the multi-disease resistance verification facilities. To promote multi-environment verification of disease resistance and adaptability, national and international joint research is a very important strategy. Though the wheat varieties with wide-adaptability and multiresistance are unable to overcome various disasters completely, they can reduce losses of yield and ensure relatively stable harvest.

Acknowledgments We thank S.Y. Chen, S. Rong, W.J. Xue, Z. Li, S.M. Mu, G. C. Zhong,

L.Z. Gao, B. Q. Li and X.Y. Zhang in Northwest Institute of Botany, Chinese Academy of Science for their contributions in this work. We also thank Prof. Z. A. Pretorius from the University of the Free State, South Africa, for his help on stem rust test. In addition, we thank Prof. Xueyong Zhang, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences for his presenting of this work on behalf of Prof. Z.S. Li during the 12th International Wheat Genetics Symposium. This work was supported by the grants from the National High-Tech Research and Development Program of China (No. 2011AA1001), the National Natural Science Foundation of China (No. 31171539), and Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDA08000000).