Banca de QUALIFICAÇÃO: MAIARA CRISTINA METZDORF DA SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : MAIARA CRISTINA METZDORF DA SILVA
DATA : 15/12/2021
HORA: 08:00
LOCAL: Alta Floresta, MT.
TÍTULO:

Phenotypic and molecular characterization of cassava landraces cultivated in settlements in the municipalities of Alta Floresta and Paranaíta, Mato Grosso state, Brazil.

PALAVRAS-CHAVES:

Euphorbiaceae, Manihot esculenta, ISSR, genetic variability, conservation. 

PÁGINAS: 80
GRANDE ÁREA: Ciências Biológicas
ÁREA: Genética
SUBÁREA: Genética Vegetal
RESUMO:

Manihot esculenta Crantz belongs to the Euphorbiaceae family, popularly known as cassava or manioc, it receives different names depending on the region of cultivation. The cultivation of cassava is largely carried out by family farmers, who exchange propagation materials (branches) and intensify the migration of the species, contributing to the maintenance of a wide genetic diversity existing in the fields. The study aimed to carry out a survey and phenotypic and molecular characterization of the landraces cultivated by small farmers in the North of the State of Mato Grosso, Brazil. The research was carried out in three settlements, Nossa Senhora Aparecida (NSA), Júlio Firmino Domingues (JFD) in the municipality of Alta Floresta and the São Pedro settlement (SP) in the municipality of Paranaíta. The survey and phenotypic characterization were carried out during visits to the farmers' plantations in the three settlements. The data collected in the field were tabulated in an Excel spreadsheet, and the frequency of cultivation and the frequency of the phenotypic classes of each descriptor were calculated. To evaluate the genetic diversity, leaf samples of each landrace were collected for DNA extraction. A total of 33 properties were visited, 76 cassava landraces were surveyed and characterized, identifying 22 individuals with different names. The “Cacau” cassava showed high frequency, cultivated in 69.7% of the properties, being the dominant landrace in the three settlements. Morphological characterization using 13 qualitative descriptors revealed a total of 44 phenotypic classes, evidencing genetic variability among the landraces evaluated in the field. Through the UPGMA method, duplicity was observed between two landraces JFD26 (“roxa” cassava) and JFD42 (unidentified) sharing the same phenotypic characteristics. For molecular characterization, the 15 ISSR primers amplified 223 fragments, revealing 95% of polymorphism. Genetic dissimilarity values ranged between 0.091 and 0.618. The groupings by the UPGMA method formed 9 distinct groups, the GI was the most representative (44.47%), the GVII, GVIII and GIX groups allocated only one individual each, respectively the individuals NSA1 (“copinha” cassava), NSA20 (“amarela” cassava) and JFD25 (“cacao” cassava). The Nei (*H) and Shannon (*I) diversity indices demonstrated the existence of genetic variability within the settlements and AMOVA indicated that the greatest genetic diversity is present within the settlements (76%). The analysis of the population structure using Structure formed two groups, according to the value of ΔK. The GI allocated the 42 individuals from the NSA and JFD settlements in the municipality of Alta Floresta, the GII was formed by the 34 individuals from the SP de Paranaíta settlement. Through the survey carried out in the NSA, JFD and SP settlements, it was possible to identify a wide diversity of cassava landraces existing in the fields of family farmers. Phenotypic and molecular characterization revealed that there is genetic variability among individuals of M. esculenta. Most of the genetic diversity is within the settlements. This diversity can be used in the construction of active germplasm collections and in future breeding programs.

MEMBROS DA BANCA:
Presidente - 32143004 - ANA APARECIDA BANDINI ROSSI
Externo ao Programa - 292282001 - JULLIANE DUTRA MEDEIROS
Externo à Instituição - EULÁLIA SOLER SOBREIRA HOOGERHEIDE - EMBRAPA
Externo à Instituição - GABRIEL MORENO BERNARDO GONÇALVES - UENF