Effects of submergence stress at the vegetative growth stage on hybrid rice growth and grain yield in China

Cyclic 3-hydroxymelatonin (c3OHM) is a major metabolite of melatonin in plants produced by the enzymatic action of melatonin 3-hydroxylase (M3H). However, the function of c3OHM in plants is unclear. Here, we report that M3H mRNA and c3OHM levels display diurnal rhythms with peaks at night, but not in a circadian manner. This diurnal rhythmicity occurred predominantly in the late vegetative growth stage (8 weeks after germination), but was absent in the early vegetative growth stage. Transgenic rice plants overexpressing or underexpressing M3H were generated to investigate the physiological roles of diurnal production of c3OHM. The M3H-overexpression (OE) line exhibited higher M3H activity and c3OHM production than the wild-type, and vice versa for the M3H‑underexpression rice (RNAi). The seedling growth phenotype of the OE and RNAi lines was comparable to that of the wild-type but exhibited pleiotropic phenotypic defects at the reproductive stage, such as decreased height, biomass, grain yield, and fertility. Of note, the OE rice showed significantly increased numbers of secondary tillers and panicles. The increase in tiller number of the OE line was linked to increased expression of tiller-related genes, such as MOC1 and TB1, suggesting that the diurnal rhythm of c3OHM production is associated with the tiller number, a pivotal agronomic trait governing grain yield in rice.

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Phosphorus fertilization in inbred and hybrid rice

Dhaka University Journal of Biological Sciences ◽

10.3329/dujbs.v19i2.8962 ◽

1970 ◽

Vol 19 (2) ◽

pp. 181-187

Author(s):

MR Islam ◽

PK Saha ◽

SK Zaman ◽

MJ Uddin

Keyword(s):

Grain Yield ◽

Key Words ◽

Hybrid Rice ◽

Phosphorus Fertilization ◽

Phosphorus Fertilizer ◽

Yield Difference ◽

P Balance ◽

Rice Genotypes ◽

Boro Rice

Five phosphorus rates (0, 5, 10, 20 and 30 kg P/ha) were tested with four rice genotypes in Boro (BRRI dhan36, BRRI dhan45, EH1 and EH2) and T. Aman (BRRI dhan30, BRRI dhan49, EH1 and EH2) season. Phosphorus rates did not influence grain yield irrespective of varieties in T. Aman season while in Boro season P response was observed among the P rates. Application of P @ 10 kg/ha significantly increased the grain yield. But when P was applied @ 20 and 30 kg P/ha, the grain yield difference was not significant. The optimum and economic rate of P for T. Aman was 20 kg P/ha but in Boro rice the optimum and economic doses of P were 22 and 30 kg/ha, respectively. Hybrid entries (EH1 and EH2) used P more efficiently than inbred varieties. A negative P balance was observed up to 10 kg P/ha. Key words: Response; Phosphorus fertilizer; Inbred; Hybrid rice DOI: http://dx.doi.org/10.3329/dujbs.v19i2.8962 DUJBS 2010; 19(2): 181-187

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Population quality and grain yield construction of mid-season indica hybrid rice “Wandao153” under different N applications

CHINESE JOURNAL OF ECO-AGRICULTURE ◽

10.3724/sp.j.1011.2008.01083 ◽

2009 ◽

Vol 16 (5) ◽

pp. 1083-1089

Author(s):

Wen-Ge WU

Keyword(s):

Grain Yield ◽

Hybrid Rice ◽

Indica Hybrid Rice ◽

Population Quality

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Variable-rate in corn sowing for maximizing grain yield

Scientific Reports ◽

10.1038/s41598-021-92238-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Eder Eujácio da Silva ◽

Fábio Henrique Rojo Baio ◽

Daniel Fernando Kolling ◽

Renato Schneider Júnior ◽

Alex Rogers Aguiar Zanin ◽

...

Keyword(s):

Grain Yield ◽

Vegetative Growth ◽

Maximum Yield ◽

Influential Factors ◽

Plant Population ◽

Seeding Density ◽

Corn Yield ◽

Growth Indices ◽

Experimental Conditions ◽

Soil Attributes

AbstractSowing density is one of the most influential factors affecting corn yield. Here, we tested the hypothesis that, according to soil attributes, maximum corn productivity can be attained by varying the seed population. Specifically, our objectives were to identify the soil attributes that affect grain yield, in order to generate a model to define the optimum sowing rate as a function of the attributes identified, and determine which vegetative growth indices can be used to predict yield most accurately. The experiment was conducted in Chapadão do Céu-GO in 2018 and 2019 at two different locations. Corn was sown as the second crop after the soybean harvest. The hybrids used were AG 8700 PRO3 and FS 401 PW, which have similar characteristics and an average 135-day cropping cycle. Tested sowing rates were 50, 55, 60, and 65 thousand seeds ha−1. Soil attributes evaluated included pH, calcium, magnesium, phosphorus, potassium, organic matter, clay content, cation exchange capacity, and base saturation. Additionally, we measured the correlation between the different vegetative growth indices and yield. Linear correlations were obtained through Pearson’s correlation network, followed by path analysis for the selection of cause and effect variables, which formed the decision trees to estimate yield and seeding density. Magnesium and apparent electrical conductivity (ECa) were the most important soil attributes for determining sowing density. Thus, the plant population should be 56,000 plants ha−1 to attain maximum yield at ECa values > 7.44 mS m−1. In addition, the plant population should be 64,800 plants ha−1 at values < 7.44 mS m−1 when magnesium levels are greater than 0.13 g kg−1, and 57,210 plants ha−1 when magnesium content is lower. Trial validation showed that the decision tree effectively predicted optimum plant population under the local experimental conditions, where yield did not significantly differ among populations.

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Impact of Different Water Management Regimes on the Growth, Productivity, and Resource Use Efficiency of Dry Direct Seeded Rice in Central Punjab-Pakistan

Agronomy ◽

10.3390/agronomy11061151 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1151

Author(s):

Sadam Hussain ◽

Saddam Hussain ◽

Zubair Aslam ◽

Muhammad Rafiq ◽

Adeel Abbas ◽

...

Keyword(s):

Grain Yield ◽

Hybrid Rice ◽

Water Productivity ◽

Dry Weight ◽

Cost Ratio ◽

Yield Attributes ◽

Benefit Cost Ratio ◽

Direct Seeded ◽

Total Dry Weight ◽

Benefit Cost

Dry direct-seeded rice has been shown to save irrigation water and labor. Nonetheless, irrigation management in dry direct-seeded rice has received very little attention. Here, we examined the potential of different irrigation regimes: aerobic rice (AR), alternate wetting and drying (AWD) and continuous flooding (CF) in dry direct-seeded rice cultivation on two rice cultivars (Pride-1 (hybrid indica) and NB-1 (inbred indica)). Growth, yield attributes, grain yield, total water input, water productivity and benefit cost ratio were measured. Our results showed that AR saved 11.22 and 28.40%, and 5.72 and 32.98% water compared with AWD and CF during 2018 and 2020, respectively. There was a significant difference in grain yield among treatments and cultivars. AWD and CF produced statistically same total dry weight and grain yield, while AR reduced the total dry weight by 31.34% and 38.04% and grain yield by 34.82% and 38.16% in comparison to AWD and CF, respectively, across the years. Except for 1000-grain weight and harvest index in AWD and CF, further differences in total dry weight and grain yield among irrigation treatments were primarily correlated with variations in yield attributes. Among the cultivars, hybrid rice performed better than inbred rice. Over the two-year period, hybrid rice increased total dry weight, grain yield, and water productivity by 9.28%, 13.05%, and 14.28%, respectively, as compared to inbred rice. Regarding water productivity (WP), the maximum percentage (40.90 and 26.53%) was recorded for AWD compared to AR and CF. Among cultivars, more water productivity (14.28%) was calculated for hybrid rice than inbred one. Chlorophyll and carotenoid contents, leaf area index and crop growth rate contributed to higher grain yield of hybrid rice under AWD and CF. In contrast to WP, the maximum benefit cost ratio was estimated to be higher for CF than that of AR and AWD. For the cultivars, the maximum value (2.26 in 2018 and 2.32 in 2020) was calculated for hybrid rice compared with the inbred one. In conclusion, these results suggests that AWD with maximum WP and CF with maximum BCR could be more efficient approaches than AR. Under CF, hybrid rice cultivars with higher yield and yield-related attributes, WP and BCR performed better.

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Optimizing Planting Density and Impact of Panicle Types on Grain Yield and Microclimatic Response Index of Hybrid Rice (Oryza sativa L.)

International Journal of Plant Production ◽

10.1007/s42106-021-00150-8 ◽

2021 ◽

Author(s):

Guotao Yang ◽

Xuechun Wang ◽

Farhan Nabi ◽

Hongni Wang ◽

Changkun Zhao ◽

...

Keyword(s):

Relative Humidity ◽

Light Intensity ◽

Grain Yield ◽

Hybrid Rice ◽

Plant Density ◽

Oryza Sativa L ◽

Planting Density ◽

Response Index ◽

Lower Position ◽

High Plant Density

AbstractThe architecture of rice plant represents important and complex agronomic traits, such as panicles morphology, which directly influence the microclimate of rice population and consequently grain yield. To enhance yield, modification of plant architecture to create new hybrid cultivars is considered a sustainable approach. The current study includes an investigation of yield and microclimate response index under low to high plant density of two indica hybrid rice R498 (curved panicles) and R499 (erect panicles), from 2017 to 2018. The split-plot design included planting densities of 11.9–36.2 plant/m2. The results showed that compared with R498, R499 produced a higher grain yield of 8.02–8.83 t/ha at a higher planting density of 26.5–36.2 plant/m2. The response index of light intensity and relative humidity to the planting density of R499 was higher than that of R498 at the lower position of the rice population. However, the response index of temperature to the planting density of R499 was higher at the upper position (0.2–1.4%) than at the lower position. Compared with R498, R499 at a high planting density developed lower relative humidity (78–88%) and higher light intensity (9900–15,916 lx) at the lower position of the rice population. Our finding suggests that erect panicles are highly related to grain yield microclimatic contributors under a highly dense rice population, such as light intensity utilization, humidity, and temperature. The application of erect panicle rice type provides a potential strategy for yield improvement by increasing microclimatic conditions in rice.

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Performance of hybrid rice grown from separated tillers

Journal of the Bangladesh Agricultural University ◽

10.3329/jbau.v17i4.44619 ◽

2019 ◽

Vol 17 (4) ◽

pp. 507-513

Author(s):

FN Kamarum Munira ◽

Md. Parvez Anwar ◽

Sabina Yeasmin ◽

Md. Harun Or Rashid ◽

Mst Farzana Rahman ◽

...

Keyword(s):

Grain Yield ◽

Plant Height ◽

Hybrid Rice ◽

Rice Variety ◽

Field Laboratory ◽

Split Plot ◽

Rice Seeds ◽

Four Levels ◽

Plot Design

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during July to November 2016 to investigate the performance of separated tillers of hybrid rice variety Dhani Gold. The experiment comprised three times of tiller transplantation viz. 3, 4 and 5 week aged tiller seedlings and four levels of number of tiller seedlings transplanted hill-1 viz. 2, 3, 4 and 5 tiller seedlings hill-1 laid out in a split plot design with 3 replications. The highest plant height was obtained when 3-week aged tiller seedlings were transplanted at the rate of 3 tiller seedlings hill-1. The highest number of total tillers hill-1 and number of effective tillers hill-1 were found when 3-week aged tiller seedlings were transplanted with 5 tiller seedlings hill-1. The highest grains panicle-1 was obtained when 4-week aged tiller seedlings were transplanted with 5 tiller seedlings hill-1. The highest grain yield was found when 3-week aged tiller seedlings were transplanted with 5 tiller seedlings hill-1. The lowest grain yield was found when 5-week aged tiller seedlings were transplanted with 2 tiller seedlings hill-1 in hybrid rice variety Dhani Gold. Based on the findings of the present study it may be concluded that 3-week old tiller seedlings of Dhani Gold should be transplanted at the rate of 4 or 5 tiller seedlings hill-1 for higher yield. Thus present study confirms the potentiality of growing hybrid rice from separated tillers in case of unavailability of seedlings or to minimize the seed cost of high value hybrid rice seeds. J Bangladesh Agril Univ 17(4): 507–513, 2019

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