To evaluate the impact of climate change on maize production, accurately measuring the radiation use efficiency (RUE) of maize is critical.  This study focused on three maize cultivars in Jilin Province, China: Zhengdan 958 (ZD958), Xianyu 335 (XY335), and Liangyu 99 (LY99).  Under the optimal growing conditions for high density planting (9 plants m^–2), the maize RUE was determined during the vegetative and reproductive phases, and the entire growth period.  The results showed that the canopy light interception for maize peaked during anthesis.  After anthesis, maize plant biomass continued to accumulate.  The maize RUE was calculated based on the absorbed photosynthetically active radiation (APAR).  During the entire growth period, maize RUE averaged 5.71 g MJ^–1 APAR among the three cultivars, with a high-to-low order of ZD958 (5.85 g MJ^–1 APAR)>XY335 (5.64 g MJ^–1 APAR)>LY99 (5.07 g MJ^–1 APAR).  Within the vegetative and reproductive growth periods, maize RUE averaged 6.85 and 5.64 g MJ^–1 APAR, respectively.  When utilizing maize models that depend on RUE to predict aboveground biomass accumulation, such as APSIM, the current RUE value of 3.6 g MJ^–1 APAR is considerably lower than the measured value obtained under high-density optimal growing conditions.  Consequently, to derive the optimal potential yield for maize in such planting conditions, we recommend adjusting the RUE to a range of 5.07–5.85 g MJ^–1 APAR.

Stone fruits, also known as drupes, have evolved an extremely hard wood-like shell called a stone to protect the seeds.  Recently, the market value of stoneless cultivars has risen dramatically, which highlights the need to cultivate stoneless fruit.  Therefore, determining the underlying mechanism of fruit stone development is urgently needed.  By employing the stone-containing jujube cultivar ‘Youhe’ and two stoneless Chinese jujube cultivars, ‘Wuhefeng’ and ‘Daguowuhe’, we comprehensively studied the mechanism of fruit stone development in jujube.  Anatomical analysis and lignin staining revealed that the stone cultivar ‘Youhe’ jujube exhibited much greater lignin accumulation in the endocarp than the two stoneless cultivars.  Lignin accumulation may be the key factor in fruit stone formation.  By analyzing the transcriptome data and identifying differentially expressed genes (DEGs), 49 overlapping DEGs were identified in the comparisons of ‘Youhe’ jujube vs. ‘Wuhefeng’ jujube and ‘Youhe’ jujube vs. ‘Daguowuhe’ jujube.  ZjF6H1-3 and ZjPOD, which are involved in lignin synthesis, were identified among these DEGs.  The overexpression and silencing of ZjF6H1-3 and ZjPOD in wild jujube seedlings further confirmed their roles in lignin synthesis.  In addition, two bHLH transcription factors were included in the 49 overlapping DEGs, and bHLH transcription factor binding motifs were found in the promoters of ZjF6H1-3 and ZjPOD, indicating that bHLH transcription factors are also involved in lignin synthesis and stone formation in Chinese jujube.  This study provides new insights into the molecular networks underlying fruit stone formation and can serve as an important reference for the molecular design and breeding of stoneless fruit cultivars of jujube and fruit trees.