Buckwheat Germplasm in the World

By Meiliang Zhou, Ivan Kreft and Sun-Hee Woo

Buckwheat Germplasm in the World offers an overview of this globally important crop, including its general characterization and genetic diversity—particularly in Russia, China, India and Eastern Europe. The book presents the latest research on molecular marker development, genetics and phenotype analysis of new wild buckwheat to examine the nutritional values of this pseudocereal crop. Due to its short growth span, ability to grow at high altitudes and the high quality of its protein content, buckwheat is considered an important crop for addressing global food needs. Ideal for researchers and advanced-level students seeking better understanding of the buckwheat germplasm.

• Summarizes all the reported and distributed buckwheat species in the world
• Offers researchers the ability to exchange resources with each other to breed new cultivars
• Classifies buckwheat species based on perennial and annual from their growth span, and self-incompatible or self-compatible from their flower morphology and characterization
• Facilitates hybridization of different species

• Language: English
• Publisher: Academic Press
• Release date: Jan 11, 2018
• ISBN: 9780128110072

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industry.

Preface

Meiliang Zhou, Ivan Kreft, Galina Suvorova, Yu Tang and Sun Hee Woo

Three-sided buckwheat grain is an interface between past and future buckwheat generations. In the past, buckwheat plants were inter-pollinated, which generated and maintained genotype diversity. The buckwheat plants which were most suitable for survival and propagation in each actual environment were able to maintain their place in the field and in the population. Thus, for example, buckwheat populations in high altitude areas accumulated genes for the synthesis of metabolites, protecting plants against UV radiation, as well as against pests and diseases. Human-made environments were conducive to plants with higher yields and larger grain, and to those resistant to lodging and grain-shedding. Different populations and domestic varieties were developed in diverse environments and with different cultivation techniques.

Buckwheat seeds and cultivation moved eastwards from the most probable area of origin of cultivated buckwheat in the Eastern Himalayas over China to Korea and Japan. It also moved westwards to Bhutan, Nepal, North India, and probably further west. Caravans and merchants on the Silk Road apparently took buckwheat grain with them to West China and further west. The Black Sea region, once dominated by Greeks and Tatars, was probably an important station for the spread of buckwheat cultivation, as suggested by words for the plant derived from Greek (Gryka, Grečka, Grechiha) or Tatar. After the 14th century, buckwheat had thus spread over most of Central Europe. As an undemanding and low-input crop, it was used as a contingency food source and a lifesaver, especially for the poor. Much later, buckwheat cultivation was spread by migrants from Europe, or directly from Asia, to North and South America and Australia. Recently, some buckwheat is also grown in Africa.

Through the centuries, different domestic cultivars of buckwheat developed—depending on the diversity of environment, the manner of cultivation, and the utilization value, with a plethora of various genes. Such material is an important natural and cultural heritage of mankind. It is important to preserve these precious materials, not only in long-term seed storage facilities (gene banks), but also by cultivation and development of new cultivars, based on the diversity of the preserved genetic material and its utilization value. Part of the important natural heritage are also the wild relatives of cultivated buckwheat. Some new discoveries of the wild relatives, also presented in this book, show that the wild buckwheat species are still not sufficiently investigated and utilized in buckwheat breeding.

The previous book Molecular Breeding and Nutritional Aspects of Buckwheat (Editors M. Zhou, I. Kreft, S. H. Woo, N. Chrungoo, and G. Wieslander), published in 2016 by Elsevier (and its imprint Academic Press), was presented at the 13th International Symposium on Buckwheat and the General Assembly of International Buckwheat Research Association, Cheongju and Bongpyeong, South Korea (September 7–11, 2016) and it received a lot of attention and appreciation.

At the 13th International Symposium on Buckwheat and IBRA Assembly some other decisions were made, which are important for further international cooperation in the field of buckwheat. The president of IBRA for the period 2016–19 became Sun Hee Woo, professor at the Department of Crop Science at the Chungbuk National University, Cheongju, South Korea. The 14th International Symposium on Buckwheat and IBRA Assembly will take place in Shillong and Shrinagar in India, which is represented by Nikhil K. Chrungoo and Jai Chand Rana.

Toshiko Matano, Ohmi Ohnishi, and Kiyokazu Ikeda and their colleagues were greatly appreciated for editing Fagopyrum (scientific journal on buckwheat research), which was published in the period 1995–2016 in Japan (Ina-Minamiminowa, Kyoto, and Kobe respectively); the suggestion of the previous editors of Fagopyrum to move the head office of the journal in 2017 back to Ljubljana, Slovenia, under the editorship of I. Kreft and his colleagues, was confirmed. It was also confirmed that September 3rd is designated as the World Day of Buckwheat to commemorate the day in 1980 when in Ljubljana, Slovenia, the International Buckwheat Research Association (IBRA) was established.

We expect that the present book, an important source in buckwheat research, the chapters of which have been well written by scientists who have contributed significantly to the research of buckwheat plant genetic resources, will be of much advantage and pleasure to readers interested in buckwheat genetic resources and related fields.

Chapter One

Overview of Buckwheat Resources in the World

Meiliang Zhou¹, Yu Tang², Xianyu Deng³, Chen Ruan³, Ivan Kreft⁴, Yixiong Tang⁵ and Yanmin Wu⁵,    ¹Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China,    ²Sichuan Tourism University, Chengdu, China,    ³Kunming University of Science and Technology, Kunming, Yunnan, China,    ⁴Nutrition Institute, Ljubljana, Slovenia,    ⁵Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China

Abstract

Buckwheat is a dicotyledonous herb which belongs to the Polygonaceae family and the Fagopyrum genus. Buckwheat is a joint name of two cultivated species, common buckwheat (Fagopyrum esculentum Moench) and Tartary buckwheat (Fagopyrum tataricum Gaertn). Though it is actually not a kind of triticeae, the usages of buckwheat seeds (achenes) are quite similar to graminaceous crops, so the agriculturists judge it as a kind of triticeae. Various popular names given to buckwheat have been used to trace its migration through Asia and Europe and are still used to confirm the origin of buckwheat. Today common buckwheat is called ogal in India, mite phapar in Nepal, jare in Bhutan, grecicha kul’turnaja in Russia. grechka in Ukraine and gryka, tatarka gryka, or poganka in Poland. It is called pohanka in the Czech Republic and Slovakia. In Sweden it is bovete, in Denmark boghvede, and in Finland common buckwheat is tattari. In Slovenia it is ajda, hajdina, or idina, in Bosnia, Serbia, Montenegro, and Croatia it is heljda. In France it is called sarrasin, blé noir, renouée, and bouquette; in Breton (North-Western France) it is gwinizh-du, in Italy fagopiro, grano saraceno, sarasin, and faggina, and in Germany Buchweizen or Heidekorn (Hammer 1986). In Korean it is maemil. It is referred to as soba in Japan where the same word also is used for buckwheat noodles. In Mandarin common buckwheat is called tian qiao mai while Tartary buckwheat is referred to as ku qiao mai. Buckwheat is widely cultivated around the world and in some areas it is a major crop. Buckwheat seeds are rich in proteins with well-balanced amino acid composition, fibers, vitamins and minerals. The content of flavonoids, a kind of bioactive substance, is also substantial. Treated as a functional food, buckwheat has drawn the attention of the wider world.

Keywords

Common buckwheat; Tartary buckwheat; global cultivation; global distribution; Fagopyrum genus; plant genetic resources; seed samples; germplasm resources

Buckwheat is a dicotyledonous herb which belongs to the Polygonaceae family and Fagopyrum genus. Buckwheat is a joint name of two cultivated species, common buckwheat (F. esculentum Moench) and Tartary buckwheat (F. tataricum Gaertn). Although it is actually not a kind of triticeae, the usage of buckwheat seeds (achenes) are quiet similar to graminaceous crops, so the agriculturists judge it as a kind of triticeae. Various popular names given to buckwheat have been used to trace its migration through Asia and Europe and are still used to confirm the origin of buckwheat. Today common buckwheat is called ogal in India, mite phapar in Nepal, jare in Bhutan, and grecicha kul’turnaja in Russia. grechka in Ukrainian and gryka, tatarka gryka, or poganka in Poland. It is called pohanka in the Czech Republic and Slovakia. In Sweden it is bovete, in Denmark boghvede, and in Finland common buckwheat is tattari. In Slovenia it is ajda, hajdina, or idina, in Bosnia, Serbia, Montenegro, and Croatia it is heljda. In French it is called sarrasin, blé noir, renouée, bouquette; in Breton (North-Western France) it is gwinizh-du, in Italy fagopiro, grano saraceno, sarasin, faggina, and in Germany Buchweizen or Heidekorn (Hammer, 1986). In Korean it is maemil. It is referred to as soba in Japan where the same word also is used for buckwheat noodles. In Mandarin common buckwheat is called tian qiao mai while Tartary buckwheat is referred to as ku qiao mai.

Buckwheat is widely cultivated around the world and in some areas it is a major crop. Buckwheat seeds are rich in proteins with well-balanced amino acid composition, fibers, vitamins, and minerals. The content of flavonoids, a kind of bioactive substance, is also substantial. Treated as a functional food, buckwheat has drawn the attention of the wider world.

The Origin and Diffuseness of Cultivated Buckwheat

Over a century ago, the Swiss plant taxonomist De Candolle (1883) raised the theory of a buckwheat origin area, claiming that buckwheat originated from Siberia and the northern part of China. In 1957, Nakao (1957) pointed out that De Candolle was not correct, for there were a lot of wild buckwheat species widely spread in the southern part of China, which indicated that the southern part of China may be the original place of buckwheat rather than Siberia or the northern part of China.

Since the 1980s, Chinese agriculturists and buckwheat researchers discovered a lot of wild buckwheat species in the southwestern part of China, and based on these findings developed some new perspectives. Jiang and Jia (1992) suggested that the Daliangshan region was one of the places of origin of Tartary buckwheat, based on the large amount of wild buckwheat, special ecological conditions, folklore, and customs regarding buckwheat in this region. Li and Yang (1992) suggested that, based on the research of buckwheat history, human history, and the national history of Yunnan, buckwheat should have originated from the southwestern part of China, on the east side of the Himalayas. More specifically, Yunnan and the Daliangshan and Xiaoliangshan regions, which were the borderlands of Yunnan and Sichuan, should be the place of origin of buckwheat. Ye and Guo (1992) suggested that from the comment of botany, the southwestern part of China was not only the differentiation and spread center, but also the original place of the Fagopyrum Mill.

Ohnishi (1995,1998a,1998b,2004) studied the F. esculentum ssp. ancestrale using morphology, reproductive biology, isozyme analysis, RAPD, and AFLP, and he confirmed the wild relative species F. esculentum ssp. ancestrale as the ancestor of cultivated species F. esculentum Moench. Tsuji and Ohnishi (2000,2001a,2001b) studied the relationship between the wild relative species F. tataricum ssp. potanini and the cultivated species F. tataricum Gaertn using isozyme analysis, RAPD, and AFLP. Based on their research they suggested that the eastern part of Tibet and the joint area of Yunnan and Sichuan are the places of origin of cultivated Tartary buckwheat.

The widespread of wild buckwheat species in the southwest of China, the cultivated history of buckwheat, the national history, and the molecular systematical studies, all proved that the southwest of China was not only the distribution center and diversity center of buckwheat, but also the place of origin of the cultivated species (common buckwheat and Tartary buckwheat). These comments are now widely accepted.

Murai and Ohnishi (1995) proposed that after being domesticated in the southwestern part of China, buckwheat was spread through two routes: one from the southwest to the north of China, then further to the Korean peninsula and later to Japan; and the other one from China through Tibet to Bhutan, Nepal, and India, and then spread to Poland through Kashmir. Buckwheat had a long cultivation history in all the East Asian countries and their neighborhoods. In the days of 800 AD, buckwheat was the most important food in Japan. Around 1200 to 1300 AD, buckwheat spread to Europe through Siberia and the south of Russia. Ukraine, Germany, and Slovenia were perhaps among the first countries with cultivated buckwheat in Europe, and then Belgian, French, Italian, and English people began to cultivate buckwheat in the 17th century. After the 17th century, the Dutch brought buckwheat to America. Now, buckwheat is common in many countries which cultivate grain crops.

Germplasm Resources of Buckwheat in the World

After thousands of years of cultivation and spread, cultivated buckwheat can be found in all continents except Antarctica. According to the data provided by FAO in 2014, 25 countries cultivated buckwheat at more than 50 hm²; total buckwheat cultivated acreage reached 2,008,694 hm²; and the total production was 2,056,585 t. Ranked by cultivated acreage, these countries were Russia, China, Ukraine, United States, Kazakhstan, Poland, Japan, Brazil, Lithuania, France, Tanzania, Belgium, Nepal, Latvia, Bhutan, South Korea, Slovenia, Czech Republic, Estonia, Bosnia and Herzegovina, South Africa, Hungary, Croatia, Georgia, Moldova, and Kyrgyzstan. Russia was the country with the largest cultivated acreage, and the acreage in China was about the same and over 700,000 hm². The second group of countries was Ukraine, United States, Kazakhstan, Poland, Japan, Brazil, Lithuania, and France, acreage reaching about 300,000 hm². These countries all had large cultivated acreage and a long history of buckwheat cultivation and breeding, so the cultivated buckwheat resources were plentiful and multiple varieties and types were formed. The Chinese Academy of Agricultural Science and Russia’s All-Russian Research Institute of Plant Industry had already collected more than 2000 samples of buckwheat germplasm resources each.

The countries mentioned above have mostly cultivated F. esculentum, and only a few countries have cultivated F. esculentum and F. tataricum at the same time, such as China, Nepal, Bhutan, Pakistan, and India. Among them China had the largest F. tataricum cultivated acreage and reached 250,000 hm² every year.

Wild buckwheat species are mainly distributed in China and some South Asian countries such as Nepal, Bhutan, Pakistan, and India. In China, wild buckwheat species were distributed in the southern provinces including Sichuan, Yunnan, Guizhou, Chongqing, Tibet, Shaanxi, Hunan, Hubei, Zhejiang, Anhui, Fujian, Guangdong, Guangxi, and Hainan, especially in Southwestern China including Sichuan, Yunnan, Guizhou, Chongqing, and Tibet, all the wild species can be found in this region, so this region was considered as not only the distribution center and diversity center of buckwheat, but also the birthplace of cultivated species (common buckwheat and Tartary buckwheat).

The Current Buckwheat Germplasm Research

Worldwide organized collection of buckwheat began in 1980s. Subsidized by the International Board for Plant Genetic Resources (IBPGR), botanists searched and collected wild buckwheat resources in the Himalaya Region. Since then, over 10,000 samples of buckwheat resources have been collected and half of them have come from South and East Asia. The sample numbers collected by different countries are presented in Table 1.1. (Campbell, 1997, Joshi, 1999, Chauhan et al., 2010). These resources were stored in long-term storage conditions (−20°C) or middle-term storage conditions (5°C, RH40%).

Table 1.1

Characterization and Evaluation

The characterization and evaluation of buckwheat has been carried out in many countries. China, India, Nepal, Japan, and North Korea measured the agronomic traits of buckwheat such as period of duration, plant height, number of blades, number of branches, number of flowers, thousand seed weight, plant type, color of stem, color of flowers, color of seeds, and shape of seeds. Furthermore, China, Japan, India, and some other countries did research about the quality characters of buckwheat (Yang, 1992, Chauhan et al., 2010), China investigated 1500 samples of buckwheat for the content of protein, amino acids, VE, VPP, P, Ca, Fe, Zn, Mn, Cu, and Se, and the evaluation of rutin was also continuously carried out. Recently, with the development and extensive use of molecular biology, the characterization and evaluation of buckwheat resources using molecular markers became popular. The characterization and evaluation of buckwheat established many mutant types and a group of excellent or special buckwheat resources were screened out, which makes a great contribution to the breeding of new varieties of buckwheat.

The Research About the Relationship of Fagopyrum Mill

Mill Steward (1930) classified the Polygonaceae plants in Asia, there were 10 species belonging to Fagopyrum Mill and they were described. Later Ye and Guo (1992) and Li (1998) proved and described these species and put them into Fagopyrum Mill, too. From then on, the argument about the position of Fagopyrum Mill became unified, and the Fagopyrum Mill was set up. In recent years multiple buckwheat wild species and wild-types of cultivated buckwheat were investigated in the southwest of China, (Ohnishi, 1991,1995; Ohsako and Ohnishi, 1998,2000; Li, 1998; Chen, 1999; Liu et al., 2008; Tang et al., 2010; Shao et al., 2011; Hou et al., 2015; Zhou et al., 2015), and the number of species in Fagopyrum Mill increased to more than twenty species. The investigation of wild species enriched the buckwheat germplasm resources and was of great benefit to buckwheat systematic research about the origin of cultivated buckwheat and the relationship between species in Fagopyrum Mill.

The buckwheat germplasm resources are not only the important foundation of genetics, breeding, and biotechnology but also the essential material for research into classification, systematic evolution, origin of species, and biological diversity of buckwheat. The various kinds of cultivated and wild buckwheat species contain a lot of valuable genes which are important for breeding improvement, and they also contain abundant nutritional value and can be used to improve the quality of meal and diet structure. Recently, related countries have made great progress in research into buckwheat germplasm resources. In the past 30 years results of the research into the germplasm resources of buckwheat have been remarkable. The local varieties of cultivated buckwheat species have been widely collected and carefully stored, new species of wild buckwheat have been found successively, and their good characters were digging and made good use of. We believe that, with the joint efforts of buckwheat researchers from different countries, the study of buckwheat germplasm resources will be intensified and there will be a large breakthrough in the area of breeding new varieties and exploiting new buckwheat resources.

Acknowledgments

This research was supported by the Investigation of Forage Germplasm in Central China (grant number