Use of gamma-radiotion to inscrease genetic variabaility in Jaragua grass (Hyparrhenia rufa).

Spontaneous or induced mutations provide important genetic variability,useful to many plant species breeding programs. With the objective to observe mutageniceffect of gamma radiation in Jaragua grass (Hyparrhenia rufa), seeds were irradiated withthe dose of 400 Gy from ~°Co source. The Mi generation was evaluated in the field.Different morphological characters were recorded, such as divergent racemes, awnlessspikelets, low growth, narrow leaves, and chimerism. No variation in flowering time wasspikelets, low growth, narrow leaves, and chimerism. No variobserved. A preliminary progeny test with M2 off-type and control plants showed variationwithin progeny mainly for the character divergent racemes, which presented Mendeliansegregation. Embryo sac analysis, by the clearing technique with phase contrastmicroscopy, showed the presence of single and multiple aposporous embryo sacs as well asa lower frequency of meiotic embryo sacs indicating the facultative apomictic breedingsystem of this species. Further investigation is needed to verify whether irradiation hascaused a break in apomixis.

Bibliographic Details

Main Authors:	VEASEY, E. A., VALARINI, M. J., MECELIS, N. R., ALCANTARA, P. B., ALCANTARA, V. de B. G., TULMAN NETO, A., ABBADO, M. R., CARDELLI, M. A.
Other Authors:	ELIZABETH ANN VEASEY, INSTITUTO DE ZOOTECNIA. Secao de Agronomia de Plantas Forrageiras; MARIA JOSÉ VALARINI, INSTITUTO DE ZOOTECNIA. Secao de Agronomia de Plantas Forrageiras. Bosista do CNPQ; NILZA ROCHA MECELIS, CNPGC; PAULO BARDAUIL ALCÂNTARA, INSTITUTO DE ZOOTECNIA. Secao de Agronomia de Plantas Forrageiras; VALQUÍRIA DE BEM GOMES ALCÂNTARA, INSTITUTO DE ZOOTECNIA. Secao de Agronomia de Plantas Forrageiras; AUGUSTO TULMAN NETO, CENA; MARCELA RIBEIRO ABBADO, Estagiária do INSTITUTO DE ZOOTECNIA; MARCIA ATAURI CARDELLI, INSTITUTO DE ZOOTECNIA. Secao de Agronomia de Plantas Forrageiras.
Format:	Artigo de periódico biblioteca
Language:	English eng
Published:	1998-06-08
Subjects:	Radio gama, Melhoramento genetico, Gamma irradiation, Apomixia, Capim Jaraguá, Hyparrhenia Rufa, Radiação, Semente, apomixis, plant breeding, seeds,
Online Access:	http://www.alice.cnptia.embrapa.br/alice/handle/doc/321625
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