Tissue Culture Applications To Improve Crops of Strawberries, Raspberries, and Blackberries
Patrick Malcolm

When agricultural crops are reproduced by division after several
generations, often a decline occurs in qualities such as vigor,
yield, disease resistance, plant and fruit appearance and
uniformity of size or shape. This condition of decline is
commonly called, "run out."

Strawberry plants have demonstrated this clonal decline (running
out) for many years. After growing strawberry plants for five or
more years, gardeners became accustomed to dividing a clump of
plants that contained the mother plant (oldest plant) in the
center and replanting the smaller daughter plants to be used as
seed plants the following season. Certain genetic, undesirable
changes (mutations) were brought to the surface, as seen in
daughter plants; as more and more plants were continuously grown,
generation after generation. Some of these corrupting mutations
may be visually observed as the plant vigor decelerates
(declines); the yield of strawberries is less, and sometimes the
berries are misshapen; and finally, the plants become extremely
susceptible to diseases caused by virus, bacteria, fungi, insect
susceptibility, and nematode victimization. Agricultural
researchers advised strawberry growers to discontinue old variety
lines and clones and were told to buy new, certified plants that
restore the vigor needed to increase yields of future strawberry
gardens.

This phenomenon of strawberry decline has been experienced with
other agricultural crops such as sweet potato vines, raspberry
bushes, blackberry bushes or vines, and banana trees. The problem
with banana trees has emerged as the greatest possible
catastrophe facing modern agriculture today, since bananas,
produced only by plant division and not seed, are the most
popular fruit in the world and may face extremely serious
setbacks, unless the efforts of scientists from Israel to "clean
up" the evolved, accumulated defects by using tissue culture that
could cause the commercial banana production to rebound.

Old "run out" clones of agricultural crops have in the last
decade been rejuvenated to produce unprecedented yields and to
restore confidence in a high quality product. Growers of
agricultural, commercial, crop plants can avoid clone decline,
"run out," by buying certified plants that have been grown under
strict governmental watchdog supervision, under a technique
called, "tissue culture." To "clean up" problems in weakened,
flawed clones of raspberry plants, a clump of cells is taken from
the growing tip of the plant called the apical meristem. These
cells grow rapidly and rarely contain virus or other harmful
defects and are placed within a sterile growing medium, where
they grow into a clump that develops roots and a growing shoot.
This micro-plant is grown into many other mother plants called
"nuclear stock mother plants." These mother plants are sent out
to be multiplied over and over into certified plants by nursery
propagators with a regained vigor, disease-free status and
desirable qualities that were once present in the original
profitable varieties.

One eclectic segment of agriculture that has been negatively
impacted by clonal decline, "run out," is the pick-your-own
operation, where berry plants are not replaced often by operators
with certified plants. Diseases and pests appear as a greater
threat every year. This same phenomenon of disease and pest
buildup is well known in home gardens where tomatoes, pepper
plants, and many other vegetable plants are abandoned after a few
years in favor of new soil locations. The decline of strawberry
plants, raspberry plants, and blackberry plants in pick-your-own
operations can not always be reversed by simply replanting the
site with certified plants, unless the soil is first fumigated
and sterilized. Very little attention has been paid to certify
muscadine and scuppernong grape vines to be free of virus,
bacteria and fungal infestations in pick-your-own operations.
Those grapevines are normally multiplied by various methods other
than seed planting.

Recent improvements in offering agricultural plants for
certification will ultimately insure the survival of valuable
berry crops like blackberry plants, raspberry plants, and
strawberry plants. Crops such as banana trees that are grown in
tissue culture in Israel for planting in Central America can
offer hope that commercial interruption of banana fruit will be
avoided. Recent tissue culture advancements have given commercial
growers the security of continued profits and quality, sweet
potato products to enjoy by growers and consumers.

The application of tissue culture propagation to the future of
canna bulb, (rhizome), and commercial production could save
growers who are floundering in complaints and indecision to
restore a once important agricultural crop with a promise of
future profits and a satisfied wholesale and retail customer.
This application of tissue culture to future crops of every type
that are grown by plant division will determine whether or not
those crops will survive and not "run out."




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Written by: Patrick Malcolm. Learn more about various trees
by visiting the author's website: http://www.tytyga.com