Archive

28 March 2018, Volume 25 Issue 2 Previous Issue    Next Issue
---
Orginal Article


For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

Orginal Article

Select

Sprouted Sorghum Extract Elicits Coleoptile Emergence, Enhances Shoot and Root Acclimatization, and Maintains Genetic Fidelity in indica Rice Radhesh Krishnan Subramanian, Muthuramalingam Pandiyan, Pandian Subramani, Banupriya Ramachandradoss, Chithra Gunasekar, Ramesh Manikandan 2018, 25(2): 61-72.  DOI: 10.1016/j.rsci.2017.08.005 Abstract ( )   HTML ( )   PDF (1356KB) ( )   The high growth-stimulating effect of plant extract has urged the plant biotechnologists to use natural supplements in the culture media instead of synthetic phytohormones. We advocated the effect of sprouted sorghum extract (SSE) on emergence, in vitro acclimatization, and genetic fidelity in coleoptile derived callus of indica rice variety ADT36. The use of SSE with Murashige Skoog medium efficiently acclimatized the root and shoot apical systems. A higher mat and seminal roots (3.4 g biomass) with an efficient shoot primordium elongation were observed with an increase in the concentration of SSE. Seeds treated with SSE medium showed higher germination and earlier coleoptile maturation about 48 h compared to untreated seeds, and there was a higher expression of eEF-1α with an increase in coleoptile length. B5 medium was effective on inducing embryogenic and nodular callus from 3-day-old coleoptile with 3.0 mg/L 2,4-dichlorophenoxyacetic acid and further proliferated effectively with 0.8 mg/L kinetin with a fresh weight of 180 mg. Highly significant regeneration was observed with combination of 2.5 mg/L 6-benzylamino purine and 3.0 mg/L α-naphthaleneacetic acid. The metabolic and genetic profiles of in vitro and directly cultivated plants were the same, examined through Fourier-transform infrared spectroscopy, random amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR) and R-ISSR (combination of RAPD and ISSR) markers, respectively, and thus confirming the significant efficacy of the SSE incorporated medium. Disarmed T-DNA was transformed to coleoptile derived callus through Agrobacterium tumefaciens LBA4404 and confirmed by GUS assay. The T-DNA integration was confirmed by DNA blot analysis using DNA from transient GUS-expressed explants. Thus, SSE can be used as a natural and organic supplement for organogenesis and efficient acclimatizations of shoot and root apical meristems in regenerated plants.

Select

OsSCE1 Encoding SUMO E2-Conjugating Enzyme Involves in Drought Stress Response of Oryza sativa Nurdiani Dini, Widyajayantie Dwi, Nugroho Satya 2018, 25(2): 73-81.  DOI: 10.1016/j.rsci.2017.11.002 Abstract ( )   HTML ( )   PDF (733KB) ( )   Small ubiquitin-like modifier (SUMO)-conjugating enzymes are involved in post-translational regulatory processes in eukaryotes, including the conjugation of SUMO peptides to protein substrate (SUMOylation). SUMOylation plays an important role in improving plant tolerance to abiotic stress such as salt, drought, heat and cold. Herein, we reported the isolation of OsSCE1 (LOC_Os10g39120) gene encoding a SUMO-conjugating enzyme from rice (Oryza sativa cv. Nipponbare) and its functional validation in response to drought stress. The E2 enzyme, OsSCE1, is one of three key enzymes involved in the conjugation of SUMO to its target proteins. Activated SUMO is transferred to the cysteine of an E2 enzyme and then to the target lysine residue of the substrate, with or without the help of an E3 SUMO ligase. Expression of OsSCE1 was strongly induced by polyethylene glycol 6000 (PEG6000) treatment, which suggested OsSCE1 may be involved in the drought stress response. Overexpression of OsSCE1 (OsSCE1-OX) in Nipponbare reduced the tolerance to drought stress. Conversely, the drought tolerance was slightly improved by the knockdown of OsSCE1 (OsSCE1-KD). These results were further supported by measurement of proline content in OsSCE1-OX and OsSCE1-KD transgenic lines under induced drought stress, which showed OsSCE1-KD transgenic lines accumulated higher proline content than the wild type, whereas OsSCE1-OX line had lower proline content than the wild type. These findings suggested OsSCE1 may play a role as a negative regulator in response to drought stress in rice.

Select

Growth and Physiological Performance of Aerobic and Lowland Rice as Affected by Water Stress at Selected Growth Stages Kamarul Zaman Nadzariah, Yusoff Abdullah Mohd, Othman Sariam, Kamarul Zaman Nadzirah 2018, 25(2): 82-93.  DOI: 10.1016/j.rsci.2018.02.001 Abstract ( )   HTML ( )   PDF (1066KB) ( )   Aerobic rice technology is still new in Malaysia, and information regarding MARDI Aerob 1 (MA1), the first local aerobic rice variety, is still lacking. Therefore, comparative studies were carried out to determine the physiological performance of aerobic rice variety MA1 and lowland rice variety MR253 under water stress given at the panicle initiation, flowering and ripening stages. This experiment was arranged in a randomized complete block design. Stomatal conductance (gs), chlorophyll a fluorescence (Fv/Fm), leaf relative water content (leaf RWC), and soil moisture content (SMC) as well as yield component parameters such as panicle number, grain yield and 100-grain weight were measured. Results revealed that gs and leaf RWC for both varieties decreased with depletion of SMC. The correlation study between the physiological parameters and SMC indicated that Fv/Fm was not affected by water stress, regardless of varieties. The yield components (panicle number, grain yield and 100-grain weight) for both varieties greatly decreased when water stress was imposed at the panicle initiation stage. This study showed that the panicle initiation period was the most sensitive stage to water stress that contributed to a substantial reduction in yield for both varieties. Under the aerobic condition (control), MR253 produced higher panicle number, 100-grain weight and yield than MA1. Although MR253 is bred for lowland, it is well adapted to aerobic condition.

Select

Variation in Grain Quality of Upland Rice from Luang Prabang Province, Lao PDR Xiongsiyee Vua, Rerkasem Benjavan, Veeradittakit Jeeraporn, Saenchai Chorpet, Lordkaew Sittichai, Thebault Prom-u-thai Chanakan 2018, 25(2): 94-102.  DOI: 10.1016/j.rsci.2018.02.002 Abstract ( )   HTML ( )   PDF (534KB) ( )   Luang Prabang Province is located within the area recognized as the center of rice (Oryza sativa L.) diversity in Lao PDR. This study reported on grain quality characteristics of 60 upland rice seed samples sharing 49 variety names collected from 6 villages in Luang Prabang in 2015. Most of the samples has non-pigmented pericarp, while red pericarp was found in four samples and purple in five samples. Almost all of the samples were of large grain type, with glutinous endosperm in 70% and non-glutinous endosperm in 30%. The brown (unpolished) rice was found with a wide range of grain nutritional quality, including protein (9.2% ± 0.9%), Fe (15.9 ± 6.9 mg/kg), Zn (19.6 ± 2.1 mg/kg), anthocyanin (0.774 ± 0.880 mg/g), and anti-oxidative capacity (2.071 ± 1.373 mg/g). The varieties sharing similar names had similar morphological characteristics but varied in nutritional concentration, with required confirmation in genetic variation analysis. This study found that some rice varieties with high grain quality may benefit the farmers directly or could be used in varietal improvement programs.

Select

Determinants of Adoption of Improved Rice Varieties in Northern Sindh, Pakistan Ali Chandio Abbas, Yuansheng Jiang 2018, 25(2): 103-110.  DOI: 10.1016/j.rsci.2017.10.003 Abstract ( )   HTML ( )   PDF (590KB) ( )   Adoption of certified and improved high-yielding crop varieties is important avenue for increasing agricultural productivity and improving the living standard of the farmers in developing countries. The main objective of the current study was to examine factors affecting adoption of improved rice varieties by smallholder farmers in Northern Sindh, Pakistan. The random sampling technique was used to collect data from 220 smallholder rice farmers through the face to face interview. Data were analyzed using descriptive statistics and probit regression model. The empirical results showed that year of education (P ≤ 0.093), farming experience (P ≤ 0.043), soil quality (P ≤ 0.077), farm machinery ownership (P ≤ 0.000), access to market information (P ≤ 0.055) and contact with extension agents (P ≤ 0.006) had significantly positive influence on adoption of improved rice variety, while age (P ≤ 0.053) had significantly negative effect.

Select

Estimation of Rice Evapotranspiration Using Reflective Images of Landsat Satellite in Sefidrood Irrigation and Drainage Network Taherparvar Maryam, Pirmoradian Nader 2018, 25(2): 111-116.  DOI: 10.1016/j.rsci.2018.02.003 Abstract ( )   HTML ( )   PDF (821KB) ( )   More accurate estimation of crop evapotranspiration (ETc) in a regional scale has always been one of the most important challenges. Temporal and spatial monitoring of ETc using satellite images can help to enhance accuracy of estimations. In this study, the (ETc)rice maps were produced by using statistical/experimental methods based on crop coefficient (Kc) maps derived from vegetation index (VI). Kc was estimated using four methods, including linear relationship between Kc and VI (Kc-VI), calibrated model of Kc-VI, linear relationship between Kcb (the basal crop coefficient) and VI (Kcb-VI), and calibrated model of Kcb-VI. The results showed that calibrated model of Kc-VI had a better performance compared to the other methods, with normalized root mean square errors (NRMSE), mean absolute error and root mean square error being 5.7%, 0.05 mm/d and 0.06 mm/d, respectively. (ETc)rice maps were produced by using calibrated model of Kc-VI and reference evapotranspiration (ET0) from FAO Penman-Monteith method. The NRMSE was 21.3% for using FAO Penman-Monteith method. Therefore, calibrated Kc-VI model in combining with ET0 based on the Landsat 7 ETM+ images could be provided a good estimation of (ETc)rice in regional scale, and can be applied to estimate water requirement due to the free and facilitate access.

Select

Testing of Rice Stocks for Their Survival of Winter Cold Ikehashi Hiroshi 2018, 25(2): 117-120.  DOI: 10.1016/j.rsci.2018.01.001 Abstract ( )   HTML ( )   PDF (631KB) ( )   Rice cultivation is considered to be initiated by vegetative propagation of sprout from wild perennial stocks. To test whether any presently cultivated rice cultivar can survive the winter cold or not, rice stocks of several cultivars including indica and japonica types were placed in a shallow pool from October to April in 2015-2016 and 2016-2017. During the coldest period of the winter, the bases of the stocks were placed 5-6 cm below the surface of water, where temperatures ranged from 3 ºC to 5 ºC, while the surface was frozen for two or three times and covered with snow for a day. Only one cultivar, Nipponbare, a japonica type, survived the winter cold and regenerated sprouts in the end of April or early May. A possibility to develop perennial cultivation of rice or perennial hybrid rice is discussed.