Abstract The rice cultivar SCS122 Miura has modern architecture, lodging resistance, late maturity cycle, moderate resistance to blast, high yield potential, long grains and adequate cooking quality. Industrial tests have demonstrated that the grains are suitable for parboiled rice. SCS122 Miura is recommended for all rice-producer regions of the state of Santa Catarina, Brazil.

Abstract SCS121 CL is a second-generation Clearfield(r) rice cultivar with resistance to herbicides of the imidazolinone group. The cultivar has modern plant type, lodging resistance, late maturity cycle, high yield potential, long grains and good cooking quality. The cultivar is recommended to all rice-producer regions of Santa Catarina, Brazil.

O conhecimento da base genética das cultivares de arroz é crucial para programas de melhoramento como base para o desenvolvimento de novascultivares. Este estudo foirealizado para avaliar a similaridade genética de 40 cultivares de arroz desenvolvidas no Sul do Brasil com o uso de duas ferramentas:marcadores AFLP e genealogia. A abordagem genealógica mostrou que 90% das cultivares foram desenvolvidas a partir deapenas seis pais, revelando uma base genética estreita entre essas cultivares. Apouca diversidade genética entre eles foi confirmada por meio de marcadores AFLP, uma vezque 111 marcadores polimórficos identificaram 87% desimilaridade entre as cultivares. A similaridade genética entre as cultivares lançadas pela Epagri (Santa Catarina) foi menor, comparado às cultivares lançadas pelas instituições públicas Embrapa e Irga. Este estudo demonstrouque cultivares de arroz desenvolvidasno Sul do Brasil têm base genética estreita, o que sugererisco de alta vulnerabilidade genética.

The genetic knowledge of the germplasm is crucial to the plant breeding in order todevelop new varieties. This study was carried out to evaluate the genetic similarity of 40 rice cultivarsdeveloped in Southern Brazil with the use of two tolls: genealogy and AFLP markers. The genealogy approach showed that 90% of the cultivars were developed from only six parents, revealing a narrow genetic basis among these cultivars.A little genetic diversity among them was confirmed by AFLP markers, since 111polymorphic markers identified 87% similarity among them. The geneticsimilarity among the cultivars released by Epagri in Santa Catarina state waslower, compared to that among the cultivars released by others public institutions, Embrapa and Irga. This study has demonstrated that rice cultivars developed in Southern Brazil have narrow genetic base, which suggests high genetic vulnerability risk.

The new rice cultivar, SCS118 Marques, was obtained through gamma irradiation of SCSBRS Tio Taka cultivar. SCS118 Marques presents modern architecture, lodging resistance, late maturity cycle, moderate resistance to blast, high yield potential, long grains and very high cooking quality. Industrial tests performed with SCS118 Marques showed that grains are suitable for parboiling and white rice, and it is recommended to all rice-producing regions of Santa Catarina.