The University of Chile and the University of Udine (Italy) have joined forces to create a Kiwi Breeding Program (PMG Chile-Italy), by which they hope to develop new varieties that meet the requirements of the national kiwi industry, in addition to carrying out research on the genetics of the species, focused on the generation of useful molecular markers supported in marker-assisted selections (MAS).
Biogold Sudamericana, Biotecnia, Campofrut, Copefrut, Prize, and Agricola La Ponderosa are the companies that are currently associated with this project. Meanwhile, the Federation of Fruit Producers of Chile (Fedefruta), the Fruit Exporters Association of Chile AG (ASOEX), and the Kiwi Committee have expressed interest in the program.
"The Kiwi Committee is well aware of the importance of encouraging the development of new varieties. For a long time, the kiwi industry relied on the Hayward kiwi, a variety that is very flexible geographically and productively, and that is generally resistant to pests and diseases, which characterized it as a clean and easy choice to produce. However, apart from the Hayward variety, there are currently new varieties with important conditions regarding taste or earlier harvests that have made a contribution to the supply market, where the yellow varieties play a very important role and there still is a long way to go," said Carlos Cruzat, president of the Kiwi Committee. In this context, he added, "last year the Kiwi Committee began talks with international geneticists for future programs, and we have been working with the University of Chile for three years, supporting the project it's working on with the University of Udine, in order to assess candidates for early varieties that are being tested in Europe and simultaneously here in Chile."
Regarding the characteristics desired by the Chilean kiwi industry for new varieties, Cruzat stated that, in the case of green kiwi, they expected it to taste good, have good productivity, that it was homogeneous, both in its production and storage (which is the utmost importance). As for the distribution of sizes, he said that was something that was very well handled commercially. "We would like the orchards to have higher productive potential, that the fruit was more responsive to the packaging and storage. We would also like the orchards to have a high fertility so we could choose the best fruit quality, and have more CAT-1, and zero CAT-2; that is, having well-formed cylindrical fruit with a green background that makes it more attractive," he said.
In the case of yellow varieties, "we are looking for something that is very similar: a very good post-harvest, a very good taste. Ultimately a good deal for producers, i.e. that the technical effort associated with the production cost per hectare is positive regarding total export volumes, because when a product has a good price but a low volume it can sustain itself. In general, businesses work better when cost structures are lower and they have a high-volume productivity as this makes them competitive. Therefore, what we expect is to have new options of yellow and green varieties that are ready for our industry, for our climate and our requirements," stated Cruzat.
The six-year program is a FONDEF project that became operational in March 2011 and is currently in its fifth year of implementation, a period in which it is in the evaluation stage of the Sorelli variety (that has a yellow pulp), which was obtained at the Italian university.
"The University of Udine was already carrying out a breeding program and they wished to collaborate with us. They are not evaluating postharvest because almost everything is for the domestic market, however we do need to study the postharvest," said Claudia Jorquera, from the Breeding and Fruit Quality Laboratory of the University of Chile. "We're doing a test with different storage periods that will provide information about the fruit's potential post-harvest life, a topic that also interests the Italians who created the variety," said Jorquera.
The relationship with the Italian University is reciprocal, as Chile is working with one of its partners, while a member of the Chilean team is in Italy dedicated to seeing the second part of the project, which is related to the genetic map of the kiwi and finding molecular markers linked to fruit quality.
In this regard, Pia Rubio, head of the Experimental Unit of the University of Chile, said a key point was that, through the kiwi's genetic, researchers could develop a marker that helps to discriminate, for example, the plant's sex. "This is key in the kiwi, as it is a species that has male and female plants, and the former are pollinators while the latter aren't," she said.
"Molecular markers are biotechnological tools that help make some processes of the selection of genotypes more efficient," she stated. The project, she added, focuses on achieving quality fruit, therefore, "the priority are female plants, which produce fruit," said Rubio.
In this sense, sex determination is a characteristic that will be used to make the breeding operation more effective. As for the quality of the fruit, it will be analyzed paying special attention to certain characteristics: fruit size, flesh texture, soluble solids, flesh color, dry matter and acidity.
The project, which does not consider transgenics, will characterize the full Actinidia spp. genebank by phenotypes and genotypes, which will serve as a basis to maintain the potential parents of the PMG Chile-Italy. "This project is the starting point, as there was no breeding program, the idea is that this continues. Competing against New Zealand is very powerful and a breeding program requires a fairly large investment and years of research," said Claudia Jorquera.
PSA resistant varieties
Another of the materials incorporated into the project is the PSA (Pseudomonas syringae pv. actinidiae), a disease that severely affects kiwi and that was detected in Chile a few years ago. "From now on, one can not continue to generate varieties without taking into account this disease. Our challenge is to focus on varieties that are more resistant, susceptible/tolerant to the disease," said Pia Rubio. "In Italy, researchers have noticed that some of their crosses have resisted, survived, so we are looking into the possibility of bringing this material," said Claudia. She stated that the project wouldn't generate a new variety, but that it might create the basis for creating a new variety that could hit the market, "that's why we have to create a model for selection," she said.
"We're just starting. We have the support of the industry. We do not expect to be like New Zealand, but we do want varieties; a variety of Chilean kiwi with a good postharvest and that is less susceptible to Psa. We want a variety that is an alternative to what already exists," she said.
Currently some of the problems facing the Chilean kiwi are that the fruit softens and becomes mealy. Additionally, the fruit is very susceptible to ethylene. In face of this, researchers are also studying the softening. Trials began with the Hayward variety, and the idea is to bring the investigation to a second season, where they also evaluate the Sorelli variety.
Finally, it's worth noting that along with the Italian materials, the research team plans to bring materials from China.
Source: elrancaguino.cl