Avaliação da resposta ao fotoperíodo em genótipos de arroz irrigado

Streck, Nereu Augusto; Bosco, Leosane Cristina; Michelon, Simone; Rosa, Hamilton Telles; Walter, Lidiane Cristine; Paula, Gizelli Moiano de; Câmera, Cátia; Lago, Isabel; Marcolin, Élio

doi:10.1590/s0006-87052006000400001

Cited by 12 publications

(16 citation statements)

References 16 publications

(8 reference statements)

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“…These results are in agreement with previous reports that developmental cycle in rice is related to FLN, i. e., the greater the FLN the longer the developmental cycle (Streck et al, 2006b). Among sowing dates, FLN was greater in early sowing dates and lower in late sowing dates, which is also in agreement with previous studies (Streck et al, 2006a). This wide range in FLN due to different genotypes and sowing dates provides a rich data set to test the hypothesis of this study, which was that the HS can be used as a plant morphological indicator to identify PD in rice and red rice, and that the HS at PD varies among genotypes and among sowing dates.…”

Section: Resultssupporting

confidence: 91%

“…Freitas et al (2006) found that PD occurs when there are seven fully expanded leaves on the main stem and did not vary among three genotypes varying in developmental cycle and in three sowing dates. Streck et al (2006a) showed that final leaf number (FLN) varied among seven rice cultivars and among sowing dates. Combinning the results by Yin & Kropff (1998) and Streck et al (2006a) implies that the NL at PD varies among genotypes and sowing dates, which is conflicting with the results reported by Freitas et al (2006).…”

Section: Introductionmentioning

confidence: 99%

“…Streck et al (2006a) showed that final leaf number (FLN) varied among seven rice cultivars and among sowing dates. Combinning the results by Yin & Kropff (1998) and Streck et al (2006a) implies that the NL at PD varies among genotypes and sowing dates, which is conflicting with the results reported by Freitas et al (2006). The objective of this study was to determine the main stem HS and the number of leaves left to emerge until flag leaf at panicle differentiation in several cultivated rice genotypes and in two red rice biotypes in different sowing dates.…”

Section: Introductionmentioning

confidence: 99%

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Relationship between panicle differentiation and main stem leaf number in rice genotypes and red rice biotypes

Streck

Lago

Bosco

et al. 2009

Sci. agric. (Piracicaba, Braz.)

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Panicle differentiation (DP) is a key developmental stage in rice (Oryza sativa L.) because at this stage plant switches from vegetative to reproductive development and source-sink relation changes to allocate part of the photoassimilates for growing spikelets and kernels. The objective of this study was to determine the main stem Haun Stage (HS) and the number of leaves that still have to emerge until flag leaf at PD in several cultivated rice genotypes and red rice biotypes in different sowing dates. A two-year field experiment was conducted in Santa Maria, Rio Grande do Sul State, Brazil, during the 2005-2006 and 2006-2007 growing seasons, and three sowing dates each year. Nine cultivated rice genotypes and two red rice biotypes were used. PD was identified as the R1 stage of the COUNCE scale, by sampling four plants from each genotype on a daily basis. When 50% of the sampled plants were at R1, the main stem HS was measured in 20 plants per genotype. The main stem final leaf number (FLN) was measured in these 20 plants when the collar of the flag leaf was visible. HS at PD is related to FLN in many cultivated rice genotypes and red rice biotypes, and that at PD, the number of leaves still to emerge until flag leaf is not constant for all the rice genotypes. These findings are not in agreement with reports in the literature.

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Section: Resultssupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Relationship between panicle differentiation and main stem leaf number in rice genotypes and red rice biotypes

Streck

Lago

Bosco

et al. 2009

Sci. agric. (Piracicaba, Braz.)

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“…The LAR calculations started at the above emergence dates and ended at the day when the flag leaf emerged, which was defined by the main stem final leaf number (FLN). The FLN depended on genotype and on emergence date, and was based on Streck et al (2006; and presented in Table 1. in rice (Streck et al, 2008a). The LAR model (Eq.…”

Section: Methodsmentioning

confidence: 99%

Leaf development of cultivated rice and weedy red rice under elevated temperature scenarios

Streck

Uhlmann

Gabriel

2013

Rev. bras. eng. agríc. ambient.

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The objective of this study was to simulate leaf development of cultivated rice genotypes and weedy red rice biotypes in climate change scenarios at Santa Maria, RS, Brazil. A leaf appearance (LAR) model adapted for rice was used to simulate the accumulated leaf number, represented by the Haun Stage, from crop emergence to flag leaf appearance (EM-FL). Three cultivated rice genotypes and two weedy red rice biotypes in six emergence dates were used. The LAR model was run for each emergence date using 100 years of synthetic daily weather data and six climate scenarios, including current, +1, +2, +3, +4 and +5 °C increase in mean air temperature, with symmetric and asymmetric increase in daily minimum and maximum temperature. The increase in air temperature scenarios decreased the duration of the EM-FL phase in the earlier emergence dates (08/20, 09/20, 10/20) whereas in mid (11/20) and late emergence dates (12/20 and 01/20) the longest EM-FL phase was in the symmetric +5 °C scenario and the shortest duration was in the asymmetric +3 and +4 °C scenarios. The timing of the onset of flooding irrigation and nitrogen dressing may be altered if global warming takes place and weedy red rice has a potential to enhance its competitiveness with cultivated rice in future climates.Key words: Oryza sativa, global warming, plant competition, climate change, nitrogen management Desenvolvimento foliar de arroz cultivado e arroz vermelho em cenários de aumento de temperatura RESUMO Objetivou-se com este estudo simular o desenvolvimento foliar de genótipos de arroz cultivados e biótipos invasores de arroz vermelho em cenários de mudança climática em Santa Maria, Rio Grande do Sul, Brasil. Um modelo de aparecimento de folhas foi usado para simular o número de folhas acumuladas, representadas pelo Estádio de Haun, a partir da emergência da cultura até o aparecimento da folha bandeira (EM-FB). Foram utilizados três genótipos de arroz cultivados e dois biótipos de arroz vermelho, em seis épocas de emergência. O modelo foi rodado em cem anos de seis cenários climáticos: atual, +1, +2, +3, +4 e +5 °C, com aumentos simétricos e assimétricos na temperatura mínima e máxima diária do ar. O aumento da temperatura nos cenários ocasiona uma redução da duração da fase EM-FB nas datas de emergência mais cedo (20/08, 20/09, 20/10) enquanto no período intermediário (20/11) e nas datas de emergência tardias (20/12 e 20/01) a maior duração da fase EM-FB foi no cenário simétrico +5 °C e a menor duração foi nos cenários assimétricos de +3 e +4 °C. O momento do início da irrigação por inundação e manejo do nitrogênio em cobertura pode ser alterado com o aquecimento global e o arroz vermelho tem potencial para aumentar sua competitividade com arroz cultivado em climas futuros. Palavras

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“…de que o desenvolvimento desta espécie seja afetado pelo fotoperíodo, já que o NFN é um indicador morfológico da resposta fotoperiódica de cultivos agrícolas anuais como o trigo e o arroz (STRECK et al, 2003;STRECK et al, 2006b). …”

Section: Resultsunclassified