Lima, Peru
May 14, 2009
Chinese farmers are rapidly
adopting a CIP-developed
potato variety that resists drought and gives much better yields
than local varieties. CIP scientists developed the Tacna variety
in 1993 and it was introduced into China in 1994 in the form of
in vitro plantlets.
After multiplication in laboratory and greenhouse, the Chinese
authorities worked with CIP scientists to evaluate the variety
for drought tolerance in the field in Hebei Highland Crop
Research Institute, Wumeng Agricultural Research Institute and
Shanxi Highland Crop Research Institute from the late 1990s
onwards. Because of its high tolerance to drought and good
yield, after several years’ evaluation, the variety was put into
the National Regional Trial for New Potato Varieties by Hebei
Highland Crop Research Institute in 2003.
Trials in 2004 and 2005 in northern China (including Hebei,
Shanxi and Inner Mongolia) showed tuber yields up 31.41 t/ha,
over 40 percent higher than Zihuabai, the most popular variety
in the region. Yet the Tacna variety produced these yields with
almost no irrigation. Tests for disease resistance also showed
that it was highly resistant to potato viruses X and Y, with
some resistance to late blight. Because of this excellent
performance, the Chinese authorities released Tacna as a new
national potato variety in 2006, naming it Jizhangshu 8. “The
performance of Tacna in China is an example of the useful
diversity for stress tolerance that has been maintained in CIP’s
lowland tropics population, and which we are now intently
rescuing by directed selection,” said Meredith Bonierbale, CIP’s
Senior Breeder.
Jizhangshu 8 has been rapidly spreading throughout China since
it was registered. Planted area was over 66 000 ha in 2008 and
the large-scale multiplication that is going on in the country
is expected to increase that area to up to 100 000 ha in 2009.
“No other new potato variety in China, maybe in the world, has
ever reach a planting area near 66 666 ha so soon after it was
registered,” said Xie Kaiyun, the head of CIP’s Liaison Office
in Beijing. The variety has been widely planted in Hebei, Inner
Mongolia, Shanxi, Gansu, Ningxia, Xinqiang, Heilongjiang, Fujian
and Guizhou, from 25 to 48 degrees north latitude, in different
agro-ecological regions.
CIP has developed elite potato breeding clones with resistance
to virus, tolerance to heat, drought and/ or salinity in the
lowland potato population. The variety Jizhangshu 8 is a product
of this breeding effort. The genetic background of the variety
Jizhangshu 8 is highly diverse and includes 3 wild and 2
cultivated species. Its parents had been pre-bred in
INTA-Argentina, Max Planck Institute-Germany, Cornell
University-USA and SPBS-Scotland and CIP. The variety Jizhangshu
8 is a clonal selection from a CIP cross, actually made in 1988
and tested during intensive research during 1989-1993 by Jorge
Espinoza and Humberto Mendoza from CIP, and Rene Chavez from
Universidad Jorge Basadre de Tacna. It was found outstanding in
the arid areas of Peru, tolerating drought and the boron
toxicity common in desert areas, and released as the variety
Tacna in collaboration with Rene Chavez of the Universidad Jorge
Basadre Grohmann, Peru. Results from evaluating potato crosses
related to the variety Tacna in north China revealed the yield
potential of such material.
Tacna, or Jizhangshu, has a growing period from 100 to 110 days
after emergence, produces about six good-sized tubers per plant,
with 16.4 mg vitamin C per 100 g fresh flesh, 17 percent starch
content and 2.25 percent protein. Its steam-cooking quality is
very good, one of the reasons for its popularity, although its
drought resistance is its outstanding distinguishing quality.
Northwest China is going through a severe drought now, one of
the more critical constraints that China is facing in increasing
food production. “With proper management and inputs, average
yields could be doubled,” said Xie Kaiyun.
Because of the high tolerance to drought and high yield
potential, this variety can reach about 30 t/ha under rain-fed
condition with annual rainfall from 300 to 400 mm and can reach
about 75 t/ha under irrigation condition. “In the early stage of
extending this variety, I could get many calls everyday from
farmers and my friends and they asked me to give them some seed
potatoes during the harvesting season. To solve the problem, all
of the nethouses in our institute were used to produce pre-basic
and basic seeds of this variety,” said Mr. Ying Jiang, the vice
president of Zhangjiangkou Academy of Agricultural Sciences, who
got the variety registered in China and Tacna had its Chinese
name, Jizhangshu 8.
“I saw Tacna growing in the field in Keshan, northeastern China,
where it had been planted for several years,” said Fernando
Ezeta, CIP’s regional leader in the area. “The health status of
the crop was good after many years without seed renewal,
possibly due to its virus resistance. It has got nice tubers and
it is quite prolific and a good yielder.”
Variedad de papa peruana es la favorita en vasta regiones
altiplánicas de China
Tacna, una variedad de papa desarrollada por el Centro
Internacional de la Papa (CIP) y lanzada al mercado por la
Universidad Jorge Basadre de esa ciudad a comienzos de los años
noventa, está causando sensación en China.
Jizhangshu, como ha sido bautizada la variedad en China, está
demostrando ser superior a muchas variedades de papa de ese país
en cuanto a rendimiento y tolerancia a la sequía. La variedad
Tacna es fruto del cruzamiento de dos especies cultivadas de
papa con tres especies silvestres encontradas en zonas áridas al
sur del Perú, que resultaron ser altamente resistentes a la
sequía y a la toxicidad con boro, un problema frecuente en los
desiertos.
Fueron los investigadores peruanos Jorge Espinoza y Humberto
Mendoza, del CIP, y René Chávez, de la Universidad Jorge Basadre
de Tacna, quienes realizaron las primeras evaluaciones en campo
antes de su liberación comercial en 1993.
Al año siguiente, Tacna fue introducida a la China como plántula
in vitro, iniciando así un largo periodo de evaluación que duró
hasta 2006 bajo las condiciones de diversas zonas altiplánicas
de China, demostrando siempre muy buenos rendimientos. Así, en
el norte de China, desde Hebei hasta Mongolia, los rendimientos
de la variedad Tacna superaron en más de 40 por ciento a los de
la variedad local más popular. Y lo mejor de todo es que tales
rendimientos se lograron con muy poco riego.
Además de su resistencia a la sequía, Tacna ha demostrado tener
tolerancia a algunas enfermedades virales de la papa y una
pequeña resistencia al tizón tardío, la enfermedad más
devastadora de la papa. Debido a su excelente calidad, las
autoridades chinas decidieron lanzarla como una nueva variedad
en 2006, denominándola Jizhangshu.
Desde entonces, Tacna –o Jizhangshu- se ha propagado rápidamente
por diferentes regiones agroecológicas del extenso territorio
chino. En 2008, el área sembrada sobrepasó las 60 mil h y debido
a la multiplicación en gran escala que se está llevando a cabo
actualmente, se espera que este año el área sembrada supere las
cien mil hectáreas.
“Ninguna otra variedad de papa de la china, y probablemente del
mundo, ha alcanzado una superficie sembrada de 66 000 h
inmediatamente después de su puesta en el mercado”, afirmó Xie
Kaiyun, el Jefe de la Oficina de Enlace del CIP en Beijing.
En Lima, Meredith Bonierbale, fitomejoradora del CIP, explicó
que este trabajo es una muestra de la utilidad de la
biodiversidad de papa que se alberga en el banco de germoplasma.
“Estamos intentando rescatar la tolerancia al estrés que poseen
algunas accesiones del banco genético del CIP, recolectadas en
tierras tropicales de baja altitud”, señaló.
Como parte de sus trabajos de mejoramiento, el CIP desarrolla
clones con resistencia a virus, tolerancia al calor, sequías y
tierras salinas. La variedad Tacna es fruto de este esfuerzo. |
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