Douglas Renato Müller

Desenvolvimento e rendimento de clones de batata na primavera e no outono

The objective of this work was to assess the effect of solar radiation, air temperature and photoperiod, in plant development and yield of potato clones grown under spring and autumn conditions. The clones SMIJ461-1, SMINIA793101-3, SMINIA97145-2 and the cultivar Macaca were cultivated during spring 2006 and autumn 2007, in Santa Maria, RS, Brazil. Leaf number at tuber initiation and at final tuberization, phylochron, accumulated thermal sum from emergence to tuber initiation and from tuber initiation to beginning of senescence, and yield were determined. The conditions of temperature and photoperiod affected accumulated thermal sum of emergence- tuber initiation and tuber initiation-beginning of senescence, yield and leaf number at tuber initiation, but did not affect phylochron and final leaf number. The accumulated thermal sum necessary to new leaf appearance depended upon each clone. New potato clones with high yield potential, for both crop conditions, can be identified through leaf number at tuber initiation under spring and autumn conditions. Season conditions have little effect on development of potato plants. The availability of solar radiation is the major atmosphere factor that explains yield variations between spring and autumn conditions in Rio Grande do Sul.

Expressão dos caracteres e seleção de clones de batata nas condições de cultivo de primavera e outono

Potato grows during spring and autumn conditions in Rio Grande do Sul, Brazil. These contrasting conditions may affect dry matter, reduced sugars, starch and amylase contents and chip color. The aim of this work was to evaluate the effect of spring and fall growth conditions in the expression of processing quality traits to develop breeding strategies to maximize the selection gain and facilitate the identification of potato clones with high processing potential. The experiment was a factorial of 21 clones and two growth seasons in the complete random design, with three replications. Tubers were produced during spring 2006 and fall 2007 growth seasons and evaluated for dry mass, reduced sugars, starch and amylase contents and chip color. Spring growth conditions maximized the gain from selection for reduced sugars, chip color, starch and amylase. Similar selection gain for dry mass was found in spring and fall seasons. The distinct environmental conditions of spring and fall did affect the selection gain and resulted in different groups of superior clones. The clones SMA508-2, SMA508-4 and SMA519-1 showed the best combination of processing quality traits in both growing conditions and higher than the best check. Clone selection for processing quality should be done in spring season, when environmental conditions improve the expression of the processing quality traits in Rio Grande do Sul State.

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.

Dormência e dominância apical de diferentes tamanhos de tubérculos de batata

The size of potato tubers produced in the same hill is an indicator of the physiological age and the time required to break dormancy and apical dominance, which is essential for the proper post-harvest management. The objective of this study was to evaluate the period of dormancy and apical dominance of different tuber sizes of three potato clones produced in the fall and submitted to two storage temperatures. Field produced tubers were harvested from ten hills per clone. The tubers were individually identified and assessed for fresh weight, length and major and minor diameters. One lot of five hills per clone was stored at 10°C and other at 20°C±2 and 85±5% relative humidity for 170 days. Breaking of dormancy and apical dominance were recorded when the tuber produced, respectively, one or two sprouts. The experiment was a factorial of three clones (SMINIA00017-6, SMIJ461-1 and Asterix), two storage temperatures (10 and 20°C) and three types of tubers (smaller diameter less than 35mm, between 35 and 45mm and larger than 45mm) in a completely randomized design. In conclusion, the results showed that physiological age varies with the size of the potato tubers, and tubers with diameter smaller than 35mm have longer dormancy than those larger than 35mm. Moreover, the storage temperature of 20°C is more effective to break the dormancy than the apical dominance.

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.

LEAF MORPHO-ANATHOMICAL CHARACTERISTICS OF FIVE POTATO CLONES

Host genetic resistance against pathogens and insects can bedirectly associated with leaf morpho-anathomical characteristics. The aimwas to study leaf morph-anatomical characteristics of five potato (Solanumspp.) clones differing in ploidy level and genetic background. The epidermisand mesophyll were characterized and stomata and trichome frequenciesdetermined in both adaxial and abaxial surfaces of plant main leaflets. Therewere no evident differences in cuticle thickness and epidermis compositionamong evaluated clones. Clones of S. microdontum Bitter and SMII had apalisade parenchyma with uniform, long and compact arranged cellscompared to other clones. There were no morphological differencesbetween stomata subsidiary and other epidermal cells. The S. microdontumclone showed the highest frequency of stomata, on the abaxial surface, andtrichomes, on both leaflet surfaces. Differences in stomata and trichomefrequencies among clones need to be accessed to find possible relationshipwith disease and/or pest resistance.