Assessment of the individual and combined effects of Rht8 and Ppd-D1a on plant height, time to heading and yield traits in common wheat

Grain yield in cereal crops is a complex trait controlled by multiple genes and influenced by developmental processes and environment. Here we report the effects of alleles Rht8 and Ppd-D1 a on plant height, time to heading, and grain yield and its component traits. Association analysis and quantitative trait locus mapping using phenotypic data from 15 environments led to the following conclusions. First, both Rht8 and Ppd-D1 a reduce plant height. However, Ppd-D1 a but not Rht8 causes earlier heading.Second, both Rht8 and Ppd-D1 a promote grain yield and affect component traits. Their combined effects are substantially larger than those conferred by either allele alone.Third, promotion of grain yield by Rht8 and Ppd-D1 a is through increasing fertile spikelet number. We speculate that Rht8 and Ppd-D1 a act independently and additively in control of plant height, grain yield and yield component. Combination of the two alleles is desirable for adjusting plant height and enhancing grain yield and abiotic stress tolerance.

CRISPR editing-mediated antiviral immunity: a versatile source of resistance to combat plant virus infections

Virus infection poses a constant threat on global crop productivity.It is estimated that virus diseases account for at least 10% of crop losses worldwide.Development of resistant crops using naturally evolved resistance genes has been a main measure for controlling plant virus epidemics.However,isolation of plant resistance genes is costly and time-consuming.Furthermore,most plant resistance genes are pathogen race-specific,with very few of them being broadly specific (Langner et al.,2018).Consequently,artificial immunity with engineered resistance to virus infections has received substantial research,which includes pathogenderived resistance,introducing single or stacked transgene into crops,and RNA interference (Shepherd et al.,2009).However,these strategies have so far achieved limited success due to narrow availability and/or fitness costs on host plants.Therefore,it is urgent to develop novel and more efficient strategies to combat plant virus infections.Recent breakthrough of CRISPR/Cas-based DNA and RNA editing tools provides a promising direction for engineering artificial immunity to plant viruses.There are now increasing reports demonstrating that CRISPR/Cas systems can be harnessed to develop antiviral immunity in plants with high efficiency and broad specificity (Table S1 in Supporting Information).