Report Bast I

Report of a visit to the All-Union Scientific and Research Institute of
Bast Crops, Glukhov, Ukrainian SSr. 5-14 July 1991 (unpublished
monograph)

S. Hennink (CPRO-DLO),
E.P.M. de Meijer (CPRO-DLO),
H.M.G. van der Werf (CABO-DLO, LUW, PAGV).

Dienst Landbouwkindig Onderzoek (DLO)
Centrum voor Plantanveredelings-en Reproduktieonderzoek (CPRO-DLO)
Droevendaalsesteeg 1
Postbus 16, 6700 AA Wageningen
The Netherlands
Telefoon: 08370-77000
Telefax: 08370-18094

CONTENTS

Preface..........................................................................1

Programme
.......................................................................1

Introduction (de
Meijer).....................................................2

Soviet hemp varieties (de Meijer)...................................3

Screening and evaluation methods (de Meijer)...........5

Genetic research (Hennink)............................................7

Breeding programme and techniques (Hennink).........8

Agronomy (van der Werf)................................................10

Harvest technology (van der Werf)................................11

Pulp and paper technology (van der Werf)..................11

Closing
Remarks................................................................13

Addresses..................................................................
..........14

PREFACE

As a result of the renewed interest for hemp cultivation in the Netherlands
many aspects of hemp became subject of a comprehensive feasibility study.
Technological aspects of the Dutch programme are maybe unprecedented, but
the agronomic and breeding research is certainly not. Hemp has a long
history as a fibre and oil crop in a large part of Europe and Asia and a
lot of useful information about this crop can be obtained from breeders and
agronomists abroad, especially in Eastern Europe and the Soviet Union.
Therefore we were very pleased to have the opportunity to visit the All
Union Scientific and Research Institute of Bast Crops in Glukhov.
Probably our trip was the first one in its kind to the Soviet-Union since
the mission of Friederich c.s. in 1964. (Reported by Friederich J.C. and
H. Sparrenberg [1967], "Teelt en verwerking van vlas en hennep in de
Soviet-Unie en Pooen."

5/7 Flight from Amsterdam-Schiphol to Moscow-Sheremetyevo, (van der Werf).
Journey by night-train to Glukhov, (van der Werf).

6/7 First acquaintance with staff of the institute. (vander Werf).

7/7 Flight from Amsterdam-Schiphol to Moscow-Sheremetyevo, (Hennink, de
Meijer). Journey by night-train to Glukhov (Hennink, de Meijer).
Visit to agronomic field trials (van der Werf).
Afternoon: Visit to department of technology and quality standards.
Visit to department of harvest mechanization.

Evening: Meeting with mayor and local authorities of Glukhov.

9/7 Journey by car from Glukhov to Kiev.
Visit to the Ukrainian Pulp and Paper Research Institute, Kiev.

10/7 Sight-seeing Kiev. Return to Glukhov.

11/7 Visit to selection field trials.
Departure and return to Moscow, return flight to Schiphol (van der Werf).

12/7 Visit to department of selection and genetics.
Excursion to Forestry department Sumy-region.

13/7 Sight-seeing Glukhov, return to Moscow.

14/7 Return flight to Schiphol (Hennink, de Meijer).


INTRODUCTION

Hemp in the Soviet-Union

Currently the basic product of hemp in the Soviet Union is the bast fibre
which is used for the production of tissue (canvas) and rope. The woody
core of the stem is mainly used for the production of chipboard. Also the
seeds are harvested for their content of edible oil, the oil cakes are used
as fodder. Depending on the primary product of the crop (seed or fibre),
different methods of cultivation are practiced (plant density and harvest
time are different), while the same varieties are used for both purposes.

About 30% of the total hemp area is primarily used for the production of
seed (seed reproduction and oil seed). Also the stems of these crops are
harvested but they are of inferior quality.

Before the revolution an area of 960,000 hectares of hemp was grown on the
present Soviet Union territory. Average straw yield was 3-4 tonnes / ha.
Fibre yield did not exceed 0.3 to 0.45 tonnes. (Reported weights of straw
and fibre include respectively 20% and 13% moisture). Average seed yield
was 0.7 to 0.8 tonnes / ha. Hemp was cultivated for the production of rope
and many kinds of tissue which were exported to Western Europe. A
sufficient quantity of hemp seed oil, mainly used as edible oil and for
production of paint, was produced to supply the domestic needs. At present
an area of about 60,000 ha of hemp remains, mainly in the Ukraine and
western parts of Russia.

The All Union Scientific and Research Institute of Bast Crops.

The All Union institute of Bast Crops was established by the Soviet
government in 1931. During the 60 years of its existence the institute has
investigated breeding, agronomy, mechanization, processing and economy of
fibre hemp. Primary processing of hemp is one of the most recent subjects.


The institute consists of five departments:

1 -- The department of selection and genetics deals with the subjects:
Establishment and maintenance of a collection of landraces, evaluation
methods, breeding, elite seed production, heredity studies (especially
heredity of fibre characteristics and sexual type) and bio technology.

2 -- The department of agricultural technology, studies the agronomy of
hemp: fertilization, crop rotation and plant density.

3 -- Department of mechanization and harvesting. Subjects: Design,
construction and testing of machinery, production of prototypes.

4 -- Department of technology and quality standards. Subjects: Retting
processes, post harvest conservation, environmental effects of retting,
quality standards for factories, price level proposals for hemp products,
organization of labour.

5 -- Department of large scale processing. Main subject: design of
machines for the hemp industry.

Besides these departments which concentrate on hemp there is also a
laboratory for selection of flax connected with the institute.
The institute owns an experimental farm of 100 ha for the implementation of
new techniques.

SOVIET HEMP VARIETIES

The collection of Soviet hemp varieties

In the past the institute gathered the local hemp varieties of the
Soviet-Union, selected landraces were introduced for cultivation in other
territories than the region of origin and / or used in breeding programs.
Accessions are multiplied under outdoors conditions, a space isolation of a
least 1 km is taken into account. The "most typical" plants according to
date of maturity, shape of flower, bract morphology, stem diameter and stem
length are selected. Seeds of at least a 100 female plants are harvested
to guarantee the populations integrity. Accessions are regenerated every
two years.

Landraces

In former times between 32 and 60 Degrees Northern latitude, hemp was a
common crop in large parts of the present Soviet territory, several local
forms (landraces) existed. The characters of the local varieties are the
result of a long process of unconscious selection by peasants during
harvesting and threshing. This selection was favourable for the early
maturing plants in the population.

At present the commonly used classification of Soviet hemp varieities is
still based on geographic origin:

-- Northern hemp (from the Leningrad region), characteristics: adapted
to short day length and low temperatures, height not more than 70 cm,
vegetation cycle 70 days, production about 2 tonnes straw / ha and low seed
yield. The fibre content is natural which means 12-15%. This group of
hemp is of no practical use at present and was only grown by peasants
before the revolution. It was cultivated for the production of tissues for
clothing and the production of oilseed.

-- Middle Russian Hemp, (central Ukraine) characteristics: 110 to 125
days from sowing to seed maturity. The yield of straw is 5-6 tonnes / ha,
seed yield 0.5 -- 2 tonnes / ha (average of 1 ton). At present fibre
content and fibre yield of the selected varieties derived from this group
are respectively 30% and 2 tonnes / ha.

-- Southern Russian hemp (South Ukraine, Caucasus and Asiatic republics,
also including far eastern hemp). Vegetation cycle of 140 to 160 days.
Yield of straw is usually more than 8 tonnes / ha, stem length sometimes
reaches 7 m. Fibre content 25%. Seed yield poor, usually less than 0.5
tonnes / ha.

The Siberian local variety Yermakovskaya, belonging to the middle Russian
group, is still used in field trials as a standard because of its excellent
fibre quality. Characteristics are: A short vegetation cycle of 105 days,
a yield of 4-5 tonnes straw / ha and 0.7 tonnes of seed. Fifteen % of
fibre of high textile quality (thin). The content of the narcotic compound
THC in this variety is higher than 0.2% which is the tolerated maximum
content in the Soviet Union.

Modern varieties

The main objectives of the hemp selection and breeding programme are: High
stem yield, seed yield, fibre content and fibre quality, monoeciousness,
low narcotic potency, and acclimatization of southern hemp types to
northern conditions.

Besides the forementioned landraces a so called intermediary group of
varieties was created. This group of varieties combines a long vegetation
period, and a good yield of straw, fibre and seed. Although this hemp is
late flowering (southerly maturing), it is adapted to cultivation in areas
where originally only middle Russian landraces were cultivated.
Intermediary varieties were bred by hybridization of selections of southern
and middle Russian hemp and afterwards family group selection. Senchenko
bred US-1 (Krasnodarskaya x Northern hemp) which combined good fibre and
seed yield, resistance, and earliness. In the nineteen-seventies US-6 was
the main variety, characteristics were: 24% fibre of good quality, 120
days vegetation cycle, good straw yield, 0.8 ton seed yield. Initially the
intermediate varieties were dioecious like the landraces where they were
derived from.

Nowadays dioecious varieties are completely replaced by monoecious
varieties. Although dioeciousness has biological advantages it is
considered to be undesirable from the economic point of view. Monoecious
(in Russian "Odnodomnaja") varieties are preferred above dioecious because
they are homogenous which allows a more easy harvest mechanization.
Another strategy, already attempted before the second world war was to
create dioecious varieties in which maturation of male and female plants
takes place simultaneously. Although these attempts were successful the
desired character disappeared after two or three cycles of multiplicaton.
Classification and genetics of the several sexual types which occur in
monoecious Cannabis populations have been subject of intensive study by Dr.
Migal in the last decennia. US-9 was the first monoecious Soviet hemp
variety. It contained a fibre content of more than 30%, but suffered from
an insect plague called Psylliodes attenuata (hop flea beetle) and also
from Orobanche ramosa. (Broomrape) Resistance was introduced by back
crossing with Southern hemp. Resistance is always acquired from the female
parent.
Currently dioecious populations are only used for breeding purposes.
The most important selections at present are several types of so called
Yuzhnaya (abbreviated: USO). Average yields of these varieties are 6-8
tonnes straw and up to 30% bast fibre. Higher fibre content (up to 40%)
is supposed to be possible but causes lodging and a decrease of fibre
quality. Hybrid F1 varieties are only used for breeding purposes. Hybrid
seed production for large scale cultivation as is common in Hungary, is
considered to be too complicated and too expensive.

Selection for low narcotic potency was started in 1973 by Dr. Virovets.
Before that time THC contents of 2% were common, at present contents of
0.1% and even of 0% occur, also the content of CBD decreased very much as a
result of this selection. Varieties with low THC content are: USO 14, USO
31, USO 16, Dneprovskaya, Zolotoskaya and Kuban.

SCREENING AND EVALUATION METHODS

In selection fields, plants are widely spaced in a density of 30 plants per
square meter with row distances of 45 cm. Fibre content and quality, seed
yield, stem yield, stem length and diameter, infection by Fusarium,
Botrytis and Sclerotinia and the concentration of narcotic compounds are
the most relevant characters that are evaluated.

Stem quality

Traditionally, textile quality parameters of stems and fibres were judged.
Important fibre quality criteria are: Durability against biological and
mechanical agents, flexibility, ability to splice, large breaking strength,
absence of impurities and an easy extraction of fibres in retting
processes. A general problem in textile hemp breeding programs is that an
increase of stem fibre content causes a decrease of fibre quality.

The improvement of evaluation methods of stems in order to accelerate the
selection procedure is the general aim of the research of the department of
technology and quality standards. Recently a new approach in judging stem
quality has been introduced, because of the possible utilization of hemp
for non traditional purposes like paper pulp production.
The clarification of the relationship between plant morphology and fibre
quality would allow indirect screening methods. Results of these
investigations are patented and therefore not published. Although details
were not discussed, we were told that only 2-3 minutes per stem is
sufficient to characterize the most important parameters.

In recently developed evaluation methods fibres are treated as a complex of
elementary fibrils located in an amout lignin and pectin complex. One of
the methods measures the density of anastomose connections between
elementary fibres. Also a method for estimating fibre lengths exists.
The characters of the xylem core are also part of the programme, especially
the level of adsorption and desorption are evaluated as measures for
cellulose quality.

Stem parameters mentioned as being relevant to judge the quality for paper
pulp production are: stem maturity, cellulose quality, level of maturity
of individual fibres and uniformity of fibre length. Additionally it would
be desirable if primary and secondary phloem contained the same amount of
lignin (which is not the case). The higher lignin content of secondary
fibres compared to primary fibres hampers a cheap production of paper pulp.
We were told that patented techniques can be bought, in the past several
patents dealing with flax were bought by French companies or institutes.

Although the main theoretical problems concerning the determination of stem
quality are solved and although prototypes of the required equipment exist,
the department showed interest in collaboration in the field of technical
improvement of the equipment.

According to staff members of the Ukrainian Pulp and Paper Research
Institute in Kiev the ideal composition of hemp stems depends on the kind
of paper which is desired. In general the lignin concentration should be
as low as possible and the lignin should be as easy as possible to remove.
Also the xylem core should be as small as possible especially because of
its difficult delignification. Although secondary bast is less desired
because it causes heterogeneity in the bast pulp this problem can
technically be solved. In general as much bast fibre as possible is
desired. There was general agreement that it is a problem to find useful
purposes for lignin and for the woody core of hemp.

Narcotic compounds

The collection of landraces was evaluated to obtain populations with low
narcotic potency. An indirect criterion for the content of the main
narcotic compount delta-9-tetrahydrocannabinol (THC) is smell and
stickiness of the female inflorescences. Indeed a selection lacking THC
and with very low content of the other major cannabinoid cannabinol (CBD),
shown to us in the field, did not possess the typical resinous smell of
normal Cannabis. Evaluation of THC content takes place at the stage of
initial seed maturity. Ten plants out of a family group of 50 are gathered
in a mixed sample and THC content in the leaf dry matter is analyzed by gas
chromatography (GC). An indirect method to predict THC content was
described by Gorskhova. The density of a specified type of resin glands is
used as a parameter for indirect screening of THC content. Glands are not
stained while using this technique. Microscopic observation shows a
dominating density of cystolithic hairs in plants with low THC content, and
a domination of iron colored trichomes in plants with high THC content.
This indirect technique together with thin layer chromatography (TLC) is
used only in the first stages of selection. At final stages gas- liquid
chromatography GLC is necessary to determine THC content. Gorshkhova's
technique is suitable for selection of individual plants, for large numbers
of plants it is to elaborate.

Diseases

Susceptibility for fungal diseases is solely observed in the field and
never in vitro Botrytis and Sclerotinia are not very important in the S.U.
due to the continental climate. Breeding for resistance does not have high
priority.
Resistance to low temperatures is not taken into account. The usual sowing
time is the second half of April and damage of seedlings by late frost does
not occur.
Nematodes or other soil borne diseases do not play any role in the breeding
programme. Hemp is believed not to suffer from these organisms. A field
trial exists with a history of 60 years of hemp cultivation without
rotation. If fertilizers, insecticides, organic fertilizer, mirco-elements
and Calcium are supplied, no yield depression can be observed after such a
period.

Fibre yield

In order to increase the yield of straw and fibre two strategies were
followed: 1; Introducing Southern varieties (long vegetation cycle) and
2; increasing fibre yield per individual stem by a selection for long thin
stems. In the second case important parameters are; diameter of stem base
and stem length. Selection aims at increasing length without increasing
the stem diameter. Parameters are: A coefficient calculated out of the
diameter of a lower stem section and the diameter of an upper section, and
a coefficient calculated out of the diameter of the stem base and the stem
length. It was concluded however that a direct determination of fibre
content is a more effective criterion for selection than calculated
indirect parameters.

The present protocol to treat individual stems is a combination of both
approaches: Measurement of stem length, diameter and weight. Subsequently
determination of fibre content of a representative segment of the stem and
a calculation of fibre content and fibre weight of the complete stem.

GENETIC RESEARCH

Sex Expression

Existing classifications of the sexual types of hemp are not suitable for
practical use in genetics and breeding. Therefore a new classification is
developed. This classification is based on the theories of Grishko (1940)
and Neuer (1943). Deviating from existing classifications of sexual
types, male and female plants segregating from monoecious hemp are not
classified as dioecious male and female type.

According to Migal's theory, sex type in dioecious hemp is determined by
two genes on the sex chromosomes, which are tightly linked. Both genes
have two alleles, the Y chromosome carrying allele M for male flowers and
allele I for loose inflorescence. The X chromosome carrying allele F for
female flowers and allele i for compact inflorescence. Allele M dominates
over F and I over i. The genotype of diploid cells carried by the sex
chromosomes is liMF [in the male] and iiFF [in the female. Besides these
genetic factors of sex chromosomes, all plants of dioecious and monoecious
hemp have a complex set of sex determining genes on autosomes. These genes
come into force when genes controlling sex on the sex chromosomes become
inactive. Autosomal factors control the sex type of monoecious hemp.
Inbreeding of monoecious hemp leads to 100% monoecious offspring. Crosses
between dioecious and monoecious hemp give mainly dioecious (female) hemp
with a small percentage monoecious hemp.

In wild dioecious hemp monoecious plants occur in a frequency ranging from
0.003 to 0.01%. Since monoeciousness is recessive and heritable a third
allele besides F and M should exist. The frequency of this allele ranges
from 0.5 to 1%. It is possible that the sex chromosome becomes inactive
when both chromosomes carry this allele. Inactivity of the sex chromosomes
is probably not caused by mutations.

The autosomes in monoecious hemp are determined by two pairs of alleles.
A the factor causing differentiation of male sex organs
G the factor causing differentiation of female sex organs
The strength (valency) can be written as AG Ag ag where A>a and G>g.

aaGG aaGg 100% female flowers
AaGG predominance of female flowers
AAGG AaGg aagg 50% male, 50% female flowers
AAGg predominance of male flowers
AAgg Aagg 100% male flowers

It is not explained how loose or compact inflorescence type is determined
in monoecious hemp

Leaf arrangement

Normally leafs on the vegetative part of the stem are arranged in opposite
pairs (decussate). In the generative part leafs are arranged spirally
(alternate).

Occasionally trifoliate plants appear (three leafs on one node).
Selection of trifoliate plants is possible. Populations with 82%
trifoliate plants were obtained. In these populations plants occur with 4
leafs per node, even plants with five leafs where found. In the trifoliate
populations the percentage of male plants was higher than in the original
population, 55% vs 45%.
In the original populations also plants appear with one leaf per node.
This form is not heritable.

Apomixis

At rare occasions two seedlings germinate from one seed. One of them is an
apomict. Often one of the two seedlings is very small. These plants
appear to be haploid.

BREEDING PROGRAMME AND TECHNIQUES

The programme has three major goals. The maintenance of existing
varieties, the selection of new varieties and the production of elite seed.

History

Before breeding started hemp yielded about 3-4 tonnes of straw per hectare
and 0.7-0.8 tonnes of seed. One ton of straw gave about 0.1-0.15 ton of
high quality fibre. In the beginning (1930's) landraces where collected.
The best landraces were selected. There were two ways for increasing
fibre yield. Improving the straw yield by use of Southern Hemp or
selecting for a longer vegetation period. The second method did not give
the wanted result, seed production declined. After a few years the
progress also stopped with the first method.

The selection for a higher fibre content started. The ratio
length/diameter of the stem was used as an indirect measure for fibre
content. Later the fibre content was determined by retting the stem.
Fibre content increased from 15% to 30%. In breeding material even 40% was
obtained. By increasing the fibre content, the quality of the fibre
declined. Therefore tests were developed to determine fibre quality, such
as purity, durability and strength. These new tests determine fibre
content in a mechanical way, so that retting was no longer needed. During
autumn and winter 30,000 till 40,000 plants can be evaluated.

In the 1930's a problem occurred with the mechanization of hemp harvest.
Dioecious male plants started retting on the field while female plants were
still green. Italian scientists and Grischko developed equal maturing
hemp. In these varieties male plants have a habitus like female plants,
but these varieties were not stable. A few years later they started the
development of monoecious hemp. Nowadays most of the Russian hemp
varieties are monoecious.
In former days conventional mass selection was used. The last decade
family selection is used.

Selection of new varieties

The Institute selects hemp for fibre and seed production. One variety may
be used for both purposes. As a seed hemp it must be early maturing and as
a fibre hemp the bast fibre content must be high, with a good fibre
quality. About 30% is the maximum fibre content, higher fibre content
decreases quality and plants become sensitive to lodging.

The main breeding objective last decade has been decreasing THC content.
The maximum content according to Soviet law is 0.2%. Most varieties have a
content of about 0.1%. The institute has recently created varieties
without THC. Variety Nr 42 yields 10 tonnes of straw or 1 ton of seed, has
a fibre content from 25 to 28% and no THC. For the selection of families
and populations in an early stage thin layer chromatography is used. In a
later stage gas liquid chromatography is used. Individual plants are
scored with the trichome method.

As basic breeding material landraces from varying origin are used. These
landraces have a high fibre quality. Southern early maturng hemp is used
for its high straw yield and its resistance against Psylliodes attenuata.
New dioecious material is crossed with a monoecious variety. This hybrid
contains only few monoecious plants so the hybrid population is backcrossed
with a monoecious variety. This population contains enough monoecious
plants for further selection. This procedure is standard for the
production of basic selection material. Selection takes place on a family
basis. It is not clear whether full sib- or half sib families are used as
a basis. Families are evaluated and selected during 10-11 years on the
field. During the evaluation of the families all male plants are removed.
The selections are evaluated on different locations in the country. By
doing this different varieties are created for different regions.

After the period of selection a selected family becomes a variety and the
variety will be multiplied for cultivation. Super elite seed is sown on an
area of 0.3 hectare, selection takes place against male and inferior
plants. Next year elite seed is sown on an area of 0.6 hectare, again
selection takes place. Two further years of multiplication is board out to
a Sovchos or Kolchos without selection. The seed then produced is used for
cultivation.
Existing varieties are maintained under continuous selection. Without
selection a variety will deteriorate and become dioecious in a few
generations.



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