Photoperiod sensitivity of very early maturing Sri Lankan rice for flowering time and plant architecture

Abstract

Unavailability of information on photoperiod sensitivity of traditional rice is a disadvantage in breeding rice for adaptation to changing climatic conditions and for optimum plant architecture. This experiment was conducted to address the above problem through determination of variation in days to flowering (DF) and morphological traits of twenty eight selected very early maturing Sri Lankan traditional rice accessions under three photoperiod conditions: short day (SD), day neutral (DN) and long day (LD). Although rice is considered to be a facultative short day plant, 12 accessions (2088, 2979, 4615, 3970, 4245, 2091, 3450, 3883, 4217, 6741, 3738 and 3677) flowered significantly late under SD over LD, while accession 4223 flowered significantly late under DN. Fifteen accessions (3943, 4042, 4734, 3693, 4513, 3845, 4390, 4144, 4220, 4223, 4237, 4387, Bg 300, At 308 and Bg 379-2) flowered significantly early under SD over LD. Four accessions (3457, 3884, 6305 and 4358) were non-responsive to photoperiod for flowering time. Plant height significantly increased only in accession 4217 under SD. Higher plant height under DN was obtained from At 308 and accession 3883. Photoperiod did not affect plant height in accession 4237 and Bg 379-2. LD only or both LD and DN conditions produced significantly higher plant height irrespective of photoperiod responsiveness for DF in rest 26 accessions. Variation in response to photoperiod for DF and plant architecture in very early maturing Sri Lankan rice indicates the potential diversity of genetic factors for photoperiod response for future use in rice breeding.

Performance of rice paddy varieties under various organic soil fertility strategies

“…To secure food particularly rice for the growing population, additional pressure on agriculture resources is expected (Yang et al 2018). National rice production can be reduced by adverse climatic and environmental conditions (Padukkage et al 2017). Maintaining soil health and restoring degraded agricultural land are the major strategies that need to be adapted.…”

Identification of Insertion/Deletion Markers for Photoperiod Sensitivity in Rice (Oryza sativa L.)

“…The heading date (flowering time) is an important trait for the regional and seasonal adaptation of rice and influences grain yield [4]. Thus, photoperiod-sensitive control in rice is essential for the production of rice adaptive to different climatic conditions [5].…”

“…The primary distinction between landrace and improved rice varieties lies in their photoperiod sensitivity [5]. Rice landraces flower under short-day conditions [5], while improved rice can flower throughout the year, given sufficient time for the preproduction stage. Previous studies on heading dates focused on genotypic photoperiod-sensitive rice cultivars [6].…”

Reproductive Development and Yield Components of Bario Sederhana Rice in Response to Photoperiod

“…It has been reported that traditional rice cultivars from tropical regions are photoperiod sensitive and require between 160-170 days to mature (Vergara & Chang,1985;Viraktamath, 2013;Nandini, 2020;Khotasena et al, 2022). Most of the studies on photoperiodism of traditional rice in the tropics are from Cambodia (Makara et al, 2001;Tsubo et al, 2009;Uch et al, 2023), Thailand (Cha-um & Kirdmanee, 2007;Boling et al, 2011;Sujariya et al, 2023), and Sri Lanka (Mapalana, 2017;Padukkage et al, 2017;Rathnathunga et al, 2019). The geographical locations of these countries are within 7.9 °N-15.9 °N latitude, thus experiencing different changes in day length throughout the year.…”