Maurício Guerra Bandinelli

Identificação de clones de batata com potencial para mesa e adaptados para os cultivos de outono e primavera do Rio Grande do Sul

Potato (Solanum tuberosum L.) is an important horticultural cropin the Rio Grande do Sul state, they are cultivated in two growing seasons,but with low yield. The tablestock is the predominant market and newcultivars should have high yield potential and good appearance to beaccepted by growers. Clonal evaluation determines its potential either asprogenitors in the breeding program or as new cultivars. The objective wasto identify potato clones with high yield, good tuber appearance andtablestock potential and adapted to two growing seasons. The clonesSMINIA90244-1, SMINIAIpora, SMINIA95043-11, SMINIA93057-1,Dakota Rose, SMIE040-6RY, SMIF165-6RY and the check cultivar Macacawere evaluated during autumn and spring of 2003 and autumn of 2004. Theexperiment was carried out in a randomized block design with fourreplications. In the average of three growing seasons, the clonesSMINIA90244-1, SMINIAIpora and the cultivar Macaca had the highesttotal yield, which is highly desirable for new cultivars. All evaluated cloneshad acceptable tuber appearance. The clone SMINIA90244-1 shared highyield and tuber number per hill and good tuber appearance. In the averageof three growing seasons, SMINIA90244-1 had tuber yield 19% higherthan the check cultivar Macaca, which should be an option as new cultivarto attend the tablestock market of Rio Grande do Sul.

Envelhecimento fisiológico de tubérculos de batata produzidos durante o outono e a primavera e armazenados em diferentes temperaturas

Adequate tuber storage is necessary to maintain a good availability of potato tubers in the market and to get seeds with adequate physiological age at planting. The objective of this work was to determine the effect of different storage temperatures on tuber physiological aging of three potato clones produced during fall and spring growing seasons. The experiment was carried out as factorial of three clones (Asterix, SMIJ461-1 and SMINIA793101-3) by four storage temperatures (4, 8, 12 and 25 oC) and two growing seasons (fall and spring) in a random design with four replications. At 30-day intervals, tubers were evaluated from the beginning to 180 days of storage. Cold storage increased dormancy period, reduced sprout number and kept health tubers. Tubers produced during fall season did not sprout at the storage temperatures of 4 and 8 oC. Tuber fresh weight loss and respiration increased with storage period and temperature. Crop growing season changes tuber physiological aging during storage. Storage in low temperature (4 and 8 oC) conditions is efficient to slow down tuber aging.

Concentração dos sais e da sacarose do meio MS na multiplicação in vitro e na aclimatização de batata

Despite the good technological understanding about in vitro micropropagation of potato, there is no information regarding plantlet behavior during acclimatization. Thus, the aim of this work was to evaluate the effect of MS salt and sucrose concentrations in the in vitro multiplication and acclimatization of potato plantlets in soilless system. The experiment was carried out in laboratory and greenhouse as a factorial in a complete random design, with four replications of 20 explants. The in vitro multiplication of three potato clones (Asterix, Macaca, and SMINIA793101-3) was assessed in different salt (half and complete medium) and sucrose (30, 45 and 60 g L-1) concentrations of the MS medium. Plantlets of each treatment were acclimatized in two soilless systems (floating and mineral substrate) under greenhouse conditions. During in vitro multiplication, there were differences among clones, except for root number. Increasing the salt concentration of the MS medium increased the number of leaves from 4.4 to 4.7, and reduced the number of roots from 3.7 to 3.4. Increasing the sucrose concentration of the MS medium reduced the number of leaves from 5.0 to 4.1 and the shoot length from 2.4 to 2.1 cm. Only the MS salt concentrations affected the ex vitro survival of potato plantlets; reducing salt concentration increased the survival from 94.8% to 97.5%. Acclimatization in soilless system is not a limiting step for the production of potato plantlets either in floating or mineral substrate, underirrigated with nutrient solution.

Produtividade e Qualidade de Tubérculo de Clones de Batata

Potato crop in Brazil depends upon European cultivars, which arenot well adapted to the growing conditions and require high amount ofagrochemicals. The objective of this work was to evaluate yield and tuberquality of potato clones to identify clones with processing potential as newcultivars and progenitors in the breeding program. The experiment wascarried out at experimental field of the Department of Fitotecnia, FederalUniversity of Santa Maria, during three growing seasons. The evaluatedclones were SMIC148-A, SMID040-4RY, SMIH095-4, SMIJ319-1,SMIJ461-1, SMIJ456-4Y, SMINIA793101-3 and the check cultivar Asterix.The experimental design was random blocks with four replications. Theclone SMINIA793101-3 had the highest tuber yield and tubers per hill,but specific gravity and chip color were unacceptable for processing. Theclones SMIC148-A, SMIJ456-4Y and SMIJ461-1 had yield similar to thecultivar Asterix; however they had higher tuber quality than the cultivarAsterix and the clone SMINIA793101-3. Any evaluated clone shared highyield and processing quality.

Plot size variation to quantify yield of potato clones

The objective of this paper was to study plot size variation among potato clones to increase experimental precision of yield performance trials. The experiment was carried out at the experimental area of the Horticulture Dept., UFSM, Santa Maria, Rio Grande do Sul State, Brazil. Tubers of five potato clones were planted in two rows of 60 hills in August 2004. For all ten experimental rows, combined plots were formed adding a different number of adjacent hills of the same row. Soil heterogeneity index and optimum plot size were estimated for each row. Real differences between treatment means for each clone and all clones were estimated using the Hatheway technique. The experimental precision of potato yield trials varied with the evaluated clone because of different optimum plot sizes. Eight-hill plots are the optimum size to quantify yield of potato clones, but experimental precision depends upon adjustments of the number of treatments and replications to the availability of experimental area. Genetic diversity indeed decreases experimental precision and justifies the use of different plot sizes. Practical applicattions and strategies to increase experimental precision of yields performance trials of potato clones are discussed.