scholarly journals Dissecting of the Deterioration in Eating Quality for Erect Panicle (Ep) Type High Yield Japonica Super Rice in Northest China

Author(s):  
Sibo Chen ◽  
Shuangjie Chen ◽  
Yihui Jiang ◽  
Qing Lu ◽  
Zhongyuan Liu ◽  
...  

Abstract Ep type is an important morphological improvement (following dwarf breeding and ideal plant type) to adapt to super high yield breeding of rice, which shows a pleiotropic effect in increasing grain yield and nitrogen use efficiency (NUE) in rice. Nevertheless, it remains unclear whether Ep has adverse effects on eating quality and its regulatory of increasing nitrogen uptake and assimilation. In this study, we developed a pair of near-isogenic lines (NILs) of dep1 (NIL-Ep, NIL-Non Ep) in the Liaogeng 5 (LG5) and Akihikari (AKI) backgrounds. Here, we report that rice plants NIL-Ep have more grain numbers per panicle in middle to bottom spike positions than plants NIL-non Ep. This part of increased grain not only is the key factor to increase the yield, but also is the reason to reduce the eating quality. The content of prolamin and glutelin in the grain increased significantly, which resulted in higher hardness and worse viscosity of rice after cooking. Additionally, the activity of several essential enzymes catalyzing nitrogen metabolism is higher in the NIL-Ep line than in NIL-non Ep line, especially from the mid to late grain filling stage. Based on these results, we conclude that Ep positively regulates grain protein accumulation primarily through enhance the activity of enzyme enroll nitrogen assimilation and redistribution during the mid to late grain-filling stage, resulting in excessive accumulation of grain protein and decreased the quality of eating.

2021 ◽  
Vol 9 (6) ◽  
pp. 405-417
Author(s):  
Mganga Joshua Fimbo Kitilu

Rice is an important cereal and staple food crop in Tanzania, the rice production has not met the demand, mainly due to water shortage. Dissemination of New Rice for Africa (NERICA) has been in progress to improve production in upland rice ecosystem. A pot experiment was conducted in a split plot design at university farm to elucidate water uptake, water use efficiency and nitrogen uptakes for two NERICA cultivars (NERICA1 and 2) and two Japanese rice cultivars ( and ). Amount of transpired water was recorded every day until maturity. Nitrogen uptake at booting and maturity growth stage were compared between these cultivars. The results indicated that amount of water transpired was greater for NERICA cultivars in the period from booting to maturity, in particular, under the dry soil condition. All the cultivars showed similar slope of regression lines between amount of transpired water and dry matter production (Water use efficiency), Nitrogen concentration per unit weight was higher in NERICA rice than in Japanese rice during grain filling stage. These results indicate that NERICA’s rice cultivars have high productivity due to higher water and Nitrogen uptake during grain filling stage compared with the Japanese rice cultivars tested.


2015 ◽  
Vol 41 (12) ◽  
pp. 1844 ◽  
Author(s):  
Xiao-Ya TIAN ◽  
Xin LIU ◽  
Qiang-Sheng WANG ◽  
Qi JIANG ◽  
Jin-Xia FENG ◽  
...  

2012 ◽  
Vol 460 ◽  
pp. 286-289 ◽  
Author(s):  
Zhen Jiang Xu ◽  
Li Zhong Xiao ◽  
Hong Liu ◽  
Yong Hao Ren ◽  
Zhi Lin Li

Based on the experiment of two inbred aromatic rice varieties and one hybrid aromatic rice line treated under four different temperatures( daymean temperature 21°C, 23°C, 26°C and 30°C respectively) during grain filling stage in phytotrons, the shape and arrangement of endosperm starch granules in rice grain transection were observed by scanning electron microscope and the related characteristics of rice grain qualities of chalky percent and chalkiness were analyzed at the same time. The results showed that under the lower temperature( daymean temperature21°C and 23°C), many large compound starch granules with clear angulars packed together regularly without significant natural gaps bewteen starch granules in the tansectional endosperm. However, with the increase of temperature, starch granules in the transectional endosperm were changed from regularly shaped and closely and orderly arranged to various shaped and chaoticly arranged with obvious natural gaps between starch granules, which was closely consistent with the poorer appearance quality under the higher temperature, which indicated that the endosperm structure is closely related with appearance quality of aromatic rice.


2019 ◽  
Vol 116 (32) ◽  
pp. 16121-16126 ◽  
Author(s):  
Ying Zhang ◽  
Yan Xiong ◽  
Renyi Liu ◽  
Hong-Wei Xue ◽  
Zhenbiao Yang

Grain size is a key factor for determining grain yield in crops and is a target trait for both domestication and breeding, yet the mechanisms underlying the regulation of grain size are largely unclear. Here we show that the grain size and yield of rice (Oryza sativa) is positively regulated by ROP GTPase (Rho-like GTPase from plants), a versatile molecular switch modulating plant growth, development, and responses to the environment. Overexpression of rice OsRac1ROP not only increases cell numbers, resulting in a larger spikelet hull, but also accelerates grain filling rate, causing greater grain width and weight. As a result, OsRac1 overexpression improves grain yield in O. sativa by nearly 16%. In contrast, down-regulation or deletion of OsRac1 causes the opposite effects. RNA-seq and cell cycle analyses suggest that OsRac1 promotes cell division. Interestingly, OsRac1 interacts with and regulates the phosphorylation level of OsMAPK6, which is known to regulate cell division and grain size in rice. Thus, our findings suggest OsRac1 modulates rice grain size and yield by influencing cell division. This study provides insights into the molecular mechanisms underlying the control of rice grain size and suggests that OsRac1 could serve as a potential target gene for breeding high-yield crops.


Sign in / Sign up

Export Citation Format

Share Document