Beautiful sunrise overgreen tea plantation.The future of teamay depend ondeveloping newvarieties to withstandthe changingenvironment (naturaland manmade) inwhich tea is grown.
Part One.
As the eco-complex of tea changes, so must much of the tea itself. Growers need new varieties of plant to help them meet the expanding disruptions of climate change, economics of global competition, soil and terrain health, pests and disease, and escalating labor shortages. An obvious instance is breeding bushes that are drought-resistant, as seasonal rainfall becomes more extreme and erratic and water supply dramatically reduced.
Growers must also adapt to shifts in customer choices, which increasingly center on the contribution to well-being, variety of flavors, botanicals, and new styles, such as kombucha, bubble, and cheese tea. They need teas that offer premium features across markets and demographics. White teas, Japanese matchas, aromatic Darjeeling black teas, and high elevation Taiwan oolongs are examples of pushing for that extra in quality that commands a premium price and customer enthusiasm by breeding a new variety that has the biologic structure to thrive in particular conditions, physical environment, and farming methods.
The products of innovation in new bushes in the field are termed clonal teas. They propagated from the biological marriage – cloning – of selected parents – maybe a regional tea that grows well at low elevations and one that looks promising in its potential extra hardiness, with fuller buds and that thrives at higher levels. The methods have a long history and demand long timetables; 20-25 years is typical. They are natural and organic, simple in concept, and very much the same as crossbreeding roses or apples through grafting. Clonals are cultivars – cultivated varieties – propagated from cuttings, rather than grown from seeds.
Today, they do not include GMO, genetically modified organisms, but they probably will within the next 10 years. Climate change is driving farming change and the more pervasive and damaging it is, the more likely it is that the boundaries on clonal tea development will be relaxed. The next wave in innovation, accelerating but still mainly exploratory, is molecular biology.
The combination of the agricultural expertise and tradition of clonal breeding and the science of molecular biology represent the base for tomorrow’s teas.
Timetable of clonal tea innovation
Question: “How do you win an Olympic gold medal? Choose your parents very carefully.” Then wait as you grow up and mature.
In tea terms, there are three main forces at work here: (1) the molecular biology of the new tea variety – the athletic potential; (2) the “biotic” ecosystem of living things of which the bushes are part, such as soil, predators, and bacteria; and (3) the non-living “abiotic” factors – supportive environments that aid or inhibit, nurture, or place stress on its growth: sun, temperature, humidity, rainfall. Then you need a coach and trainer: the skilled tea professional, grower, garden manager, artisan crafter, etc. One research study concluded that fully half the differences between harvested crop from the same seeds are accounted for by abiotic forces – a little like twin athletes attending two high schools with their different programs. Much of clonal “training” aims at enhancing or inhibiting abiotic response.
It takes 20-25 years on average for the Olympics tea candidate to be ready for full competition. It must move through juvenile stages to maturity after typically 7-10 years of research and exploration: finding suitable parents in the available and narrowing gene pool and birthing and nurturing the youngster in protected nurseries through the typical 4-6 years before it begins to produce tea, carrying out “real world” field trials over multiple harvests and registering the clonal for widespread adoption.
Then there’s three years or so to reach critical mass among farmers, many of whom are skeptical of the payoff as they must replant, adapt factory processing, and lose production today in the uncertain interest of tomorrow. They are already constrained by lack of credit and investment capital so that while they need clonal innovation to be profitable, they can’t afford it because they are not profitable.
It is well worth the effort expended on clonal development by national tea research organizations, government-directed programs, and elite tea growers and collaborations. There are a number of clonals which changed their nation’s or a region’s tea industry. India’s Darjeeling has 30 or so registered clonals that maintain the development of its gardens’ best breeds. Clonals are the base for Malawi and Kenya’s programs to improve quality, yield, and ability to compete in price-intensive and increasingly commoditizing export markets.
When you look at catalogs of the best specialty teas, Taiwan stands out for its clonals. Just about all its noted high mountain oolongs are cultivars of Qing Xing, developed in the late 1960s. Jin Xuan, known as milk oolong and Golden Lily, Red Ruby #18, and Hong Yun, a 2008 cross between a China Keemum and Asssam Kyang, were the base for Taiwan’s move to eminence in oolongs such as Alishan and the creation of premium black teas.
Japan’s Yabukita: Clonals as a transformational force
One of the most far-reaching of such developments is Yabukita, which transformed tea growing in Japan. This clonal accounts for three-quarters of Japan’s total tea growing acreage. It was first bred in the early 20th century, legally registered in 1956, and widely farmed in the 1970s. It is easy to grow, frost-resistant, and generates high yield teas with a distinctive “umani” flavor.
It’s a good general-purpose plant that meets the needs of most growers, including being well suited to mechanized harvesting – basically lawn mower cutting versus hand plucking. Yabukita is an example of monoculture: reduction of genetic variability to a single crop or variety. India’s 50,000 rice varieties are now reduced to only 50 farmed varieties. Clonal mass harvest teas similarly reduce diversity – an analogy is manicured lawns versus a wild meadow. Yabukita is vulnerable to frost damage; genetic erosion and monoculture add to weather and pest risk.
But its very narrow genetic base still makes for diverse teas through the care, skill, and craft of growers. Yabukita accounts for around 97% of tea produced in the Shizuoka prefecture and 40% of Kyoto and Kagoshima, including top grade sencha and gyokuro. It is the base for lower grade bancha, the free tea served on the side in restaurants and is overpriced. Uji sencha, one of the great teas of the world is Yabukita as are the three varieties of steamed Fukamushi greens: Futsumushi (40-60 second steaming, versus 90-120), and Chumuchi and Asamushi (20-30). A high-end clonal ingredient needs a chef.
Japan has around 70 other registered clonal teas that add genetic diversity. (China’s list of cultivars that include clones, improved clones, and seeding/cuttings adds up to 120 national and 160 regional and Taiwan about 70.) More specialized cultivars crossbreed Yabukita with — for instance — a top-grade cultivar used to produce ceremonial grade matcha (the best and not the cheap culinary grade) to add a sweeter flavor and vivid green color. (The two terms clonal and cultivar are used loosely and interchangeably in many discussions. It may be useful to think of a clonal as creating a new dynasty, with intermarriages, adoptions, and new family entrants as enabling the offspring cultivars that constitute the lineage of the family.)
Seimei is a newer cultivar aimed at the growing matcha market; it can be harvested a precious few days before a Yabukita and is more frost resistant, which extends its growing area to the North of Japan. Okunodori is a cultivar propagated from Yabukita and a wild tea; its goal is an even better sencha than the superb Uji and Kagoshima area teas.
Samidori is targeted to matcha, producing a very creamy and mellow flavor. It’s lower in yield but provides for a longer plucking season and is hardy in tolerating weather conditions. Gokou is a clonal native to the Uji region. It produces a sharper and fuller matcha, and is mainly harvested in the Kagoshima region. It was first cloned from Yabukita in 1969 and registered in 1990. Originally intended for making sencha, it is now used for gyokuro, the best of all Japan’s teas and high on the global list.
Kenya: Escaping the commodity trap
There’s a tension between propagating clonals to improve yield versus quality. The bulk tea grower segment in essence treats them as a defensive measure: more production in conditions of climate and weather change and ability to survive the growing stresses of terrain, soil condition, fertilizer needs, and pest and disease protection. Higher yield is the priority with higher quality a bonus.
Kenya’s Tea Research Institute (TRI) was explicit about the trade-offs in a 2015 statement of, “Broad objective… clones that combine high yields and acceptable tea quality.” TRI developed over 1,000 recent cultivars, of which 58 rank as highly superior and released for commercial application. Its researchers point to 14 of these as producing some of the world’s highest crop yields, three times the average for unimproved teas.
China’s Longjing Dragonwell is routinely rated one of the 10 greatest teas of the world. Its Fuding white tea is in the same class. Even here, though, the yield issue is a complement and even competitor to quality. The small Fudong and neighboring growers in Fujian’s Zhenghe County, can’t meet the expanding demands, processing precision, and prices for its Silver Needle tea. Over time clonals have added excellent Bai Mudan varieties, using the clonal Dai Bai which add yield and are generally good value for money.
Longjing similarly is being supplemented by Longjing #43. Its buds are larger and bigger. One commentator adds in passing that this is “without sacrificing much of the flavor.” How much is “much” and what does it mean for the future of the teas that are the product of a long heritage of growing – and of cloning?
Part Two (Exclusive E-magazine content)
Kenya is world’s largest exporter of basic blacks for blending in mass market tea bags. These constitute over half of UK cheap tea consumption, which fell over 20% in the past decade. They retail for under $1 an ounce, with few brands and fewer specialty teas. Clonal developments are essential in the bulk tea international market, where many regions, large producers, and smallholder farms get caught up in a commodity trap. They can’t differentiate their product and must compete in a market where costs escalate and long-term prices erode. While there are periodical boosts to prices, often driven by shortages from climatic factors, in more and more of the 10 countries that account for over 90% of exports, the general trends are a compounded cost growth of around up to 10% a year and a price decline of 7%.
Escaping the commodity trap rests on an endemic tension between yield and quality: more and cheaper tea or better and different tea. Kenya’s Purple tea is markedly better and distinctively different. The TRF301 and 302 clonals were bred over a 25-year program to pack the leaf with anthocyanins, a family of antioxidants with intense hues. This Purple tea commands a price of around $6. Anthocyanins are a family of 16 molecular compounds found in sweet fruits. They are distinctive in the color of their leaf that gives purple tea its name. The blue/purple and sweetness combination is exemplified by blueberries. Chemically, anthocyanins are powerful “radical scavengers” that attack cells that threaten health. Purple tea has strong pharmacological potential.
Clonals as “brands” in India and Taiwan
There are several clonals where quality is the only priority. AV2 from Darjeeling is a peak of traditional methods and is almost a brand in itself. It is part of the elite gardens’ collaborations that created a truly superb base for existing black teas and new oolongs, greens, and white. It’s subtly sweet and floral, with a lightness of taste and aromatic complexity. AV2 is the base for many of the elite gardens of Darjeeling crafting some of the greatest black teas of the world. Castleton, Margaret’s Hope, Giddapahar, North Tikvar, and Puttabong are examples.
AV2 is one of the most successful clonal teas. It comes from Darjeeling, where the naming is based on the estate where it was developed and brought to market, in this instance Ambari – the A – and the V being vegetative. It is the base for the best gardens in Darjeeling to make outstanding teas. Castleton Moonlight is a preeminent instance. AV2 is marked in reviews as being a “surprise”, a major innovation in flavor and characteristics that is different, not just better. It’s also often described as memorable, unexpected, and even mindblowing; ratings stress its being full, bold, and smooth and it has become a strong favorite of Darjeeling devotees. It is very dependent on environment. Poor soil leads to rapid defoliation.
AV2 competes with several gardens that combine historical pedigree and clonal innovation. B157 (originated in the Bannockburn estate) is gloriously fragrant and the “rare” and most recent P312 (Phoobsering) produces excellent teas in Risheehat, Jungpana, and Margaret’s Hope estates. All three of these clonals are used as the ingredient for teas that improve on well-established first/second flush grades, including the SFTGFOP: Still Far Too Good For Ordinary People. They extend this historical identity to the broad range of classic teas, such as Thurbo’s AV2 white and Goldpaldhara’s Maharaja oolong. Taiwan’s 25-year development of its Ruby Red #18, had a far-reaching goal: to create an ultraspecial entirely new black tea to add to the country’s superb oolongs. Here, quality, not crop yield, was the target. The result is the carefully crafted, labor intensive, and marvelously complex and aromatic Sun Moon Lake tea. It’s a clonal cross between a broad leaf cultivar from Myanmar and a variety of wild tea native to Taiwan. It’s delicate, labor-intensive, low yield, and localized and the genetic structures are totally unsuited to the needs of such producers as Bangladesh who need yield, climate adaptation, and water/nitrogen fertilizer efficiency. The best Ruby Red is sorted by hand using tweezers to avoid damaging the leaf. This is not a crop to harvest inexpensively by using machines.
The stimulus for Ruby Red was the Japanese occupation of Taiwan in 1917. Authorities wanted to develop a black tea that would reduce their dependence on British imports. They introduced the Assam variety of bush and over a 50-year period produced a clonal with flavors that are unusual, as the most common descriptors indicate: cinnamon, wintergreen mint, and honoki aroma (the scarce cypress wood used to add a subtle mild scent to a sushi board). It combines the genetic boldness of the Assam with a low astringency from the wild tea parentage.
The main growing area, Sun Moon Lake, is a reminder that clonals are environment sensitive and even environment specific. Sun Moon Lake has an ideal Assam-like climate and elevation. Taiwan has several other clonal teas where the benefit is a highly differentiated and outstanding tea. Hongyun black and Jingxuan “milk oolong” are noted examples.
These are all instances of the value of clonal propagation. But there’s so much missing. It represents the best of the long tradition of tea innovation, expertise, and craft. Much of the gap is filled by the addition to all three of these of molecular biology. This is especially powerful in the key area of parent selection. Experts emphasize just how little we know about the genetics of tea and their “functional” interaction with the complex tea germplasm.
Here are just a few figures that illustrate the complexity, analytic challenges, and tools: a single leaf contains 30,000 protein-coding and 1,500 defensive genes, 500 bioactive compounds with interactive effects on 200 diseases, 925,000 polymorphic markers, 2,200,000 QTL (quantitative trait loci) indicators of molecular interactions between genes in a medium-size data base. Genetic mapping for blister blight took 70 million reads to profile blister blight in a cultivar that left untreated or un-cloned wipes out 40% of the crop. Another modeled the interaction of 7 million gene pairs in exploring parent candidates for over 300 clonals.
The molecular network of the bud, leaf, stem, and roots
Think of the leaf as a genetic blueprint of the molecular and cellular networks that define the characteristics of a specific variety: its compounds, enzymes, secondary metabolites, amino acids, biochemical pathways, chromosomes, and antioxidants to name just a few of the most pronounceable and comprehensible. There are many thousands of others: the Ty3/gypsy retrotransposon shaped the tea genome expansion for 50 million years and, of course, serine carboxypeptidase-like acyltransferase-encoding genes are a core element in gallylated catechins that add to the palatability of teas. And, as for nucleotide sequences of ribosomal RNA maturase leaf regions in cpDNA… This language reflects the accelerating shift in clonal teas: the move from an agricultural perspective to add that of the science of molecular biology: genetic mapping, DNA markers, fingerprinting, and diversity analysis. Clonal teas have largely been built on understanding and classifying their morphology: the size, shape, and structure of visible elements and interactions of major known chemical compounds, such as caffeine, theanine, anti-oxidants, theanine, and amino acids. Roots, stems, leaves, and buds are the unit of observation. This captures what is happening in the field. One study found that tea bushes with vertical versus spreading branch angles and curved leaves that had a waxy “cuticular” waxiness were more draught tolerant. These particular morphological traits affect how much sunlight the plant absorbs – a negative force that dries out moisture more quickly and a positive one that lets it flourish if it has the needed water and nutrients. They signal a potential parent for clonal development.
Tea Heritability
Clonal teas aim at finding a new network design and making the blueprint inheritable over coming seasons and generations of farming. The blueprint instructions come packaged in its germplasm: the complete information that defines a living organism and that is inheritable. That may be a seed, tissue, cutting, pollen, or just a few cells. Clonal teas are grown by design while seed teas mainly grow by chance. They are a jumble of variety. If you look at a field of seed-grown teas, you’ll see many different leaf sizes and hues, bush heights, growth rates, etc. That reflects the how the seeds reproduce, which is a complex topic in itself. They are heterozygous, yet another word capturing their distinctive genetics. They don’t all take on the same inheritance.
Look at a field of clonal teas and you’ll see much more uniformity. Traits can be selected with each germplasm passing on the same hereditable genotype copy. It is in this sense that the germplasm is a design blueprint. National tea research labs, regional grower collaborations, and individual tea gardens can systematically search for combinations of “parent” teas and track them through years of growth, maturation, and cultivation, in nurseries first and later in the tea fields.
The tools can uniquely identify a tea varietal, its parents, area of origin, and its degree of genetic diversity. This last issue is growing in concern, with the new mapping technologies opening up a wide range of investigation. The nagging fear is inbreeding and loss of diversity as the clonal teas converge on a narrowing set of candidates for propagation. Deforestation and widespread loss of land for growing tea lose the germplasm of wild teas. Many localized tea communities preserve their historical stock or harvest wild trees. These are a resource of great potential value.
Understanding is obviously the precursor to developing. The new tools reveal such insights as the need to include response to CO2 plus the unrecognized extent to which African cultivars that added yield have poor rooting systems making them vulnerable to low moisture threshold conditions. Research disproved the widely-shared assumption that the stem of the leaf accounts for much of the aroma of oolongs. There’s now a deep understanding of the historical origins of teas and the impacts on variability and diversity. India is most diverse, followed by China, Kenya, Sri Lanka, and at the end of the list Japan and Taiwan. Italy’s few tea plants are shown to have originated in Zheyang, China.
The data issue
There’s far too little sharing between countries and labs to build a coordinated platform for research and application. There are many individual germplasm gardens whose priority is conservation of genetic diversity. The need for this increases with the reduction in farmland, deforestation, and planting of new crops that threaten older and wild gardens. There’s a general consensus in research studies and field surveys that the genetic base for “elite clonal” is now very narrow. One concern is not to lose the existing old seedling gardens whose diversity is not an asset for growing tea today but very much of value in selecting candidate germplasm for tomorrow’s.
It’s been easier to develop clonals that improve yield than ones that enhance quality. Many yield factors are measured and their physical indicators noted. But ones like color, aroma, briskness, leaf appearance, and astringency are both nonpredictable and rely on involvement of skilled tasters. Quality is impossible to predict, classify, or document. They are greatly affected by the transfer from the nursery to the field. The research literature provides thousands of examples: the plant canopy leaf exposure, morning/evening moisture, mechanized harvesting versus hand plucking, and the cutting height, nitrogen uptake, and the interactions among over 600 molecular compounds, most notably catechins, theaflavins, and gallates.
What’s coming next? Genetic engineering
One of the key aspects of clonal propagation is that it is opposite to GMO. Cloning copies — but does not alter — the genome, which is the complete set of DNA and genes. That makes it organic and natural. It also minimizes the risks that are the concerns of many consumers, policy makers, and health professionals: the Roundup controversies being the standout issue. But it seems inevitable that genetic engineering of tea is coming if not soon then sometime. With the mapping and understanding of tea genetics will come the ability to apply CRISPR – genetic scissors to snip, replace, insert, and duplicate sections of the genome: the encoded DNA/RNA sequence. Already, commentators picked out — as an “innovation” enabled by DNA fingerprinting, generatic bar coding, and markets — the protection of intellectual property. The obvious question raised: Does genetic engineering mean a tea Roundup patent and lawsuit equivalent?