Effects of Thickness Fraction Process on Physicochemical Properties, Cooking Qualities, and Sensory Characteristics of Long-Grain Rice Samples

A process of removing thinner kernels of rough rice, i.e., thickness fraction process, has been suggested as a method for increasing milling yields in the rice industry. This study aimed at determining whether physicochemical properties, cooking qualities, and sensory characteristics of rice samples could be changed by the addition of a thickness fraction into the rice process stream. Each of four long-grain rice cultivar lots was assigned into two groups: unfractionated and thickness-fractionated. For the thickness-fractionated group, thin rice kernels (<1.9 mm) of rough rice were discarded from unfractionated rice samples. Unfractionated and thickness-fractionated rice samples were compared with respect to physicochemical properties, cooking qualities, and sensory characteristics. The results showed that the removal of such thin kernels decreased the breakage and chalkiness rates and increased head rice yields. Fractionated rice samples exhibited lower amylose contents and crude protein contents but higher gelatinization temperatures than unfractionated rice samples. While the optimum cooking duration and width–expansion ratios of thickness-fractionated rice samples were higher than those of unfractionated ones, there was a negligible impact of the thickness fraction process on sensory characteristics of long-grain rice samples. In conclusion, the thickness fraction process affects physicochemical properties and cooking qualities more than the sensory characteristics of rice samples.

Efficient Genetic Transformation of Rice for CRISPR/Cas9 Mediated Genome-Editing and Stable Overexpression Studies: A Case Study on Rice Lipase 1 and Galactinol Synthase Encoding Genes

Rice is a staple food crop for almost half of the world’s population, especially in the developing countries of Asia and Africa. It is widely grown in different climatic conditions, depending on the quality of the water, soil, and genetic makeup of the rice cultivar. Many (a)biotic stresses severely curtail rice growth and development, with an eventual reduction in crop yield. However, for molecular functional analysis, the availability of an efficient genetic transformation protocol is essential. To ensure food security and safety for the continuously increasing global population, the development of climate-resilient crops is crucial. Here, in this study, the rice transformation protocol has been effectively optimized for the efficient and rapid generation of rice transgenic plants. We also highlighted the critical steps and precautionary measures to be taken while performing the rice transformation. We further assess the efficacy of this protocol by transforming rice with two different transformation constructs for generating galactinol synthase (GolS) overexpression lines and CRISPR/Cas9-mediated edited lines of lipase (Lip) encoding the OsLip1 gene. The putative transformants were subjected to molecular analysis to confirm gene integration/editing, respectively. Collectively, the easy, efficient, and rapid rice transformation protocol used in this present study can be applied as a potential tool for gene(s) function studies in rice and eventually to the rice crop improvement.

Response of Rice (Oryza sativa L.) Cultivars to Variable Rate of Nitrogen under Wet Direct Seeding in Temperate Ecology

Transplanting rice appears to pose many problems, including depletion of freshwater reservoirs and competition for labor. Conversely, direct seeding allows us to overcome shortcomings associated with conventional transplanting. Nitrogen is a crucial nutrient needed for plant growth and yield. Therefore, this study was executed to analyze the influence of nitrogen on the performance of rice genotypes grown by direct seeding in wet soil. The experiment comprised various rice cultivars, i.e., Shalimar Rice-1, Shalimar Rice-3, Shalimar Rice-4, and Jhelum, and nitrogen (N) levels, i.e., 0, 90, 120, and 150 kg/ha. Shalimar Rice-4 produced a maximum grain yield (6.39 t/ha), followed by Shalimar Rice-3 and Jhelum). The application of 150 kg N/ha showed maximum values for growth parameters, yield attributing traits, and grain yield (6.68 t/ha); however, it remained at par with 120 kg N/ha. Crop water productivity was highest in Shalimar Rice-4 (0.49 kg/m3), and the same showed a consistent increase with increasing N levels from 0–150 kg/ha, with a comparable value of 0.49 to 0.51 recorded at 120 and 150 kg N/ha. Moreover, the Shalimar Rice-1 variety required the maximum in growing degree days (GDD) and helio-thermal units (HTU) to attain different phenological stages till physiological maturity (131 days). However, the cultivar Shalimar rice-4 (SR-4) performed better by registering significantly higher heat use efficiency (HUE) (4.44 kg/ha °C/day). Additionally, the highest net return and the benefit-cost ratio were registered by Shalimar Rice-4. B:C ratio of 1.75 was realized from application of 150 kg N/ha, which remained very close to that achieved with 120 kg N/ha. In conclusion, the rice cultivar Shalimar Rice-4 with the application of 120 kg N/ha could boost rice production under DSR in water-scarce regions of temperate northern India.

Performance of double grained rice cultivar under different plant spacing

Plant spacing ensures uniform and optimum plant population and facilitates sufficient natural resources for crop growth which, in turns influences the crop yield positively. An investigation was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, during July to December 2017 to study the influence of plant spacing on the yield of double grained rice cultivar. The study comprised five spacing viz. 25 cm × 15 cm, 25 cm × 10 cm, 20 cm × 15 cm, 20 cm × 10 cm and 15 cm × 15 cm and two rice cultivars viz. a double grained rice cultivar and BRRI dhan49 and a double grained rice cultivar. It was laid out in a randomized complete block design with three replications. The double grained rice cultivar produced taller plant (155.65 cm), longer panicle (23.93 cm), higher 1000-grain weight (25.96) and higher straw yield (6.90 t ha-1), though the higher grain yield (3.68 t ha-1) was found in the test cultivar (BRRI dhan49). Planting at 20 cm × 15 cm produced the highest grain yield (3.70 t ha-1) which was at par with 25 cm × 15 cm, 25 cm × 10 cm and 20 cm × 10 cm while planting at 15 cm × 15 cm produced the lowest grain yield (3.13 t ha-1). The interaction of the double grained rice cultivar with all spacing combinations produced taller plants than the spacing combinations with BRRI dhan49. The higher grain yield (3.52 t ha-1) was found in the double grained rice cultivar with 20 cm × 10 cm spacing which was at par with the spacing of 20 cm × 15 cm and 25 cm × 15 cm, respectively; although BRRI dhan49 always produced the higher yield. The lowest grain yield (3.08 t ha-1) was recorded at the double grained rice cultivar with 25 cm × 10 cm spacing, however, the same treatment produced the highest biological yield (11.23 t ha-1) due to the highest straw yield (8.15 t ha-1). Hence, the spacing 20 cm × 15 cm might be recommended for the higher grain yield in the double grained rice cultivar Res. Agric., Livest. Fish.8(3): 273-279, December 2021

Application of local microbes increases growth and yield of several local upland rice cultivars of Southeast Sulawesi, Indonesia

Rice is the major food commodity in Indonesia and many other countries, as the main source of carbohydrate. Rice production must be increased continuously to meet food needs, one of which is by utilizing largely available dry land areas. Two important factors required to increase rice production on marginal soils are the use of high-production adaptive varieties and biological agents. It is necessary to conduct research on the application of local microbes to the cultivation of upland rice cultivars, with the aim to determine the best genotypes and/or suitable microbes. This research was carried out at the Research Field and laboratories of Faculty of Agriculture, University of Halu Oleo, from April 2020 to April 2021. The first tested factor was biological agents (local microbes), consisting of three levels, namely: without microbes (M0), the fungus Trichoderma sp. (M1), and the bacteria Pseudomonas sp. (M2). The second factor was the upland rice cultivar, which consisted of five levels, namely: V1 (Tinangge cultivar), V2 (Enggalaru cultivar), V3 (Bakala cultivar), V4 (Momea cultivar), and 1 nasional variety, namely V5 (Inpago-12 variety), as check variety. The research results showed that the interaction between local microbes Trichoderma sp. (M1) and Pseudomonas sp. (M2) on Tinangge (V1) and Momea (V4) cultivars gave a better effect on crop production. The best cultivar based on the growth and yield variables was generally obtained from the Momea cultivar (V4), although in many variables it was not significantly different from the Tinangge cultivar (V1). These cultivars could be further studied and possibly developed for promising cultivars in Kendari areas.

Seed Halopriming Improves Salinity Tolerance of Some Rice Cultivars During Seedling Stage

Background Saline land in coastal areas has great potential for crop cultivation. Improving salt tolerance in rice is a key to expanding the available area for its growth and thus improving global food security. Seed priming with salt (halopriming) can enhance plant growth and decrease saline intolerance under salt stress conditions during the subsequent seedling stage. However, there is little known about rice defense mechanisms against salinity at seedling stages after seed halopriming treatment. This study focused on the effect of seed halopriming treatment on salinity tolerance in susceptible cultivars, IR 64, resistant cultivars, Pokkali, and two pigmented rice cultivars, Merah Kalimantan Selatan (Merah Kalsel) and Cempo Ireng Pendek (CI Pendek). We grew these cultivars in hydroponic culture, with and without halopriming at the seed stage, under either non-salt or salt stress conditions during the seedling stage. Results The SES scoring assessment showed that the level of salinity tolerance in susceptible cultivar, IR 64, and moderate cultivar, Merah Kalsel, improved after seed halopriming treatment. Furthermore improved the growth performance of IR 64 and Merah Kalsel rice seedlings. Quantitative PCR revealed that seed halopriming induced expression of the OsNHX1 and OsHKT1 genes in susceptible rice cultivar, IR 64 and Merah Kalsel thereby increasing the level of resistance to salinity. The level expression of OsSOS1 and OsHKT1 genes in resistant cultivar, Pokkali, also increased but not affected on the level of salinity tolerance. On the contrary, seed halopriming decreased the level expression of OsSOS1 genes in pigmented rice cultivar, CI Pendek, but not affected on the level of salinity tolerance. The transporter gene expression induction significantly improved salinity tolerance in salinity-susceptible rice, IR 64, and moderate tolerant rice cultivar, Merah Kalsel. Induction of expression of the OsSOS1 gene in susceptible rice, IR 64, after halopriming seed treatment leads to balance the osmotic pressure by ion exclusion mechanisms, so that be tolerant to salinity stress. Conclusion These results suggest that seed halopriming can improves salinity tolerance of salinity-susceptible and moderate tolerant rice cultivars.

Crop yield prediction using CERES-Rice vs 4.5 model for the climate variability of different agroclimatic zone of south and north-west plane zone of Bihar (India)

CERES-rice models are being validated and tested across the world and vigorously used in agrotechnology transfer. Crop growth models have been considered as potential tools for simulating growth and yield of crops. Hence, DSSAT v 4.5/ CERES-Rice (Decision Support System for Agro-technology Transfer / Crop Estimation through Resource and Environment Synthesis) was applied to validate the Rice productivity from Bihar State in India. Long term historical weather data (1980-2011) and (1985-2011) from South and North West Alluvial plane zones of Bihar was used for yield analysis. Genetic coefficients required for running the CERES-Rice vs 4.5 model were derived and the performance of the model was tested under the climate variability conditions experienced by these two agroclimatic zones. Management combinations simulated were three transplanting dates (1st, 15th & 30th July) for rice cultivar Rmansuri under rainfed conditions.The results indicated that both the early and late sowing dates result in lower yields as compared to optimum sowing date of 15th July. The simulated phenology and yield were found to be in agreement with observed data suggesting that the calibrated model may be operationally used with routinely observed soil, crop management and weather parameters for Rice yield estimation from these two regions of Bihar.

Identifying mutations in sd1, Pi54 and Pi-ta, and positively selected genes of TN1, the first semidwarf rice in Green Revolution

Background: Taichung Native 1 (TN1) is the first semidwarf rice cultivar that initiated the Green Revolution. As TN1 is a direct descendant of the Dee-geo-woo-gen cultivar, the source of the sd1 semidwarf gene, the sd1 gene can be defined through TN1. Also, TN1 is susceptible to the blast disease and is described as being drought-tolerant. However, genes related to these characteristics of TN1 are unknown. Our aim was to identify and characterize TN1 genes related to these traits. Results: Aligning the sd1 of TN1 to Nipponbare sd1, we found a 382-bp deletion including a frameshift mutation. Sanger sequencing validated this deleted region in sd1, and we proposed a model of the sd1 gene that corrects errors in the literature. We also predicted the blast disease resistant (R) genes of TN1. Orthologues of the R genes in Tetep, a well-known resistant cultivar that is commonly used as a donor for breeding new blast resistant cultivars, were then sought in TN1, and if they were present, we looked for mutations. The absence of Pi54, a well-known R gene, in TN1 partially explains why TN1 is more susceptible to blast than Tetep. We also scanned the TN1 genome using the PosiGene software and identified 11 genes deemed to have undergone positive selection. Some of them are associated with drought-resistance and stress response. Conclusions: We have redefined the deletion of the sd1 gene in TN1, a direct descendant of the Dee-geo-woo-gen cultivar, and have corrected some literature errors. Moreover, we have identified blast resistant genes and positively selected genes, including genes that characterize TN1's blast susceptibility and abiotic stress response. These new findings increase the potential of using TN1 to breed new rice cultivars.

Florpyrauxifen-Benzyl Selectivity to Rice in Brazilian Conditions

Florpyrauxifen-benzyl (FPB) is a new class of auxinic herbicide developed for selective weed control in rice. This study aimed to evaluate the effect of environmental conditions, P450 inhibitors, rice cultivar response, and gene expression on FPB selectivity in rice. Field experiments established in a randomized block design showed that rice plant injury due to two FPB rates (30 and 60 g ai ha−1) was affected by planting time and rice stage at herbicide application. The injury was higher at the earliest planting season and more in younger plants (V2) than larger (V6 and R0). However, no yield reduction was detected. Under greenhouse conditions, two dose-response experiments in a randomized block design showed that spraying malathion (1 kg ha−1) before FPB application did not reduce herbicide selectivity. The addition of two P450 inhibitors (dietholate and piperonyl butoxide, 10 g a.i. seed-kg−1 and 4.2 kg ai ha−1, respectively) decreased the doses to cause 50% of plant injury (ED50) and growth reduction (GR50). However, it seems not to compromise crop selectivity. Pampeira cultivar showed lower ED50 and GR50 than IRGA 424 RI. A growth chamber experiment was conducted in a completely randomized design to evaluate the gene expression of rice plants sprayed with FPB (30 and 60 g ai ha−1). Results showed downregulation of OsWAKL21.2, an esterase probably related to bio-activation of FPB-ester. However, no effect was detected on CYP71A21 monooxygenase and OsGSTL transferase, enzymes probably related to FPB degradation. Further research should focus on understanding FBP bio-activation as the selective mechanism.