Search Results (5)

Silique dehiscence is a critical biological phenomenon in rapeseed production that significantly influences seed maturity, harvesting efficiency, and ultimately yield. As one of the world’s most important oilseed crops, studying the mechanisms underlying silique dehiscence in rapeseed (Brassica napus L.) not only aids in understanding fundamental principles of plant development but also provides a scientific basis for optimizing agricultural production practices. Silique dehiscence occurs naturally during the maturation process of rapeseed, with the timing and extent of this phenomenon directly affecting seed harvesting efficiency. This paper reviews the research progress regarding the mechanization of canola production, which enhances harvesting efficiency by enabling timely harvest coordination to minimize pre-harvest shattering losses and reduce post-harvest seed damage. Additionally, it addresses the factors influencing pod shattering, the process of pod shattering, the genes associated with this phenomenon, and the molecular mechanisms underlying pod shattering. These findings establish a foundation for a comprehensive understanding of pod shattering in canola. Full article

Rapeseed siliques easily shatter after ripening, resulting in a significant amount of grain loss, which delimits the development of rapeseed machine harvest. However, the effect of nitrogen (N) and density interaction on the characteristics of rape siliques and shattering resistance index is still vague. During the 2021–2022 and 2022–2023 growing seasons, we selected the Jiayou No. 5 rapeseed variety and set three N application levels (N1: 90 kg ha⁻¹, N2: 180 kg ha⁻¹, N3: 270 kg ha⁻¹) and two density treatments (M1: 150,000 plants ha⁻¹, M2: 300,000 plants ha⁻¹) to research the effects of N and density interaction on morphological indexes, physiological indexes, shatter resistance index and yield of direct-seeding rapeseed siliques. The silique shatter resistance index, silique’s length, weight, moisture content, silique shell’s weight, thickness, lignin content, cellulose content and phenylalaninase (PAL) activity all increased first and then decreased with the increase in the N application rate; the N2 treatment increased by 18.38% and 26.92%, respectively, compared to the N1 and N3 treatments; 3.65%, 2.48%; 6.70%, 3.58%; 20.46%, 18.33%; 5.97%, 5.96%; 8.82%, 9.60%; 9.12%, 19.90%; 43.85%, 69%; 2.10%, 11.04%. Compared with the M1 treatment, the silique shatter resistance index, silique’s length, weight, moisture content, silique shell’s weight, thickness, lignin content, cellulose content and PAL activity were lower under M2 treatment. Correlation analysis demonstrated that the silique’s length, water content, silique shell’s weight, thickness, lignin content, cellulose content and PAL activity were significantly positively correlated with the silique shatter resistance index. Therefore, this study shows that N2M1 treatment can carry off synergy between silique shatter resistance and yield. Full article

In order to reduce the silique shattering loss of the rapeseed mechanical harvesting process, based on the state of force on the silique during the rapeseed harvesting reel branch stage, Ningza 1810, Zhenyou 8, and Fengyou 306 were used as research objects, and the experimental research on the factors affecting rapeseed silique shattering was carried out using the swing impact method. The experimental analysis showed that rapeseed varieties, silique moisture content, silique growth position, collision material, impact speed, force position, and other factors had significant effects on silique shattering. The impact velocity was less than 1.5 m·s⁻¹, the difference in the effect of each factor on pod shattering was not significant, and it was not easy to shatter when the moisture content of the rapeseed silique was higher. The impact resistance of the front side of rapeseed was two to four times that of the bonding surface of rapeseed petals, the shattering rate of the top rapeseed silique was twice that of the bottom siliques, and when siliques were supported, they were more likely to shatter under external forces than when they were unsupported. The experimental study of the mechanical properties of rapeseed siliques was carried out using the impending fracture method; the experimental analyses showed that the support position and force position of the silique, the loading speed, and the growth position of the silique had a significant effect on the mechanical properties of the silique. The maximum cracking force was higher and the bending strength was stronger when the body of the silique was supported; the range of the maximum cracking force was 3.05 N to 4.16 N, and the bending strength range was 8.48 MPa to 11.57 MPa. The maximum cracking force and bending strength of the silique were stronger when the front side of the silique petal was pressurized than when the bonding surface of the petal was pressurized. Based on Pearson’s correlation and grey correlation analysis, the morphological characteristics of rapeseed siliques were ranked in order of their influence on the performance of siliques in terms of the angle between the silique and stalk, stalk diameter, petal thickness, beak length, silique thickness, silique width, and silique length. This study can be used as a reference for the design and optimization of the rapeseed harvesting reel branch mechanism and the selection of machine-harvestable rapeseed varieties. Full article

Seed shattering is an undesirable trait that leads to crop yield loss. Improving silique resistance to shattering is critical for grain and oil crops. In this study, we found that miR319-targeted TEOSINTE BRANCHED 1, CYCLOIDEA, and PROLIFERATING CELL NUCLEAR ANTIGEN BINDING FACTOR (TCPs) inhibited the process of post-fertilized fruits (silique) elongation and dehiscence via regulation of FRUITFULL (FUL) expression in Arabidopsis thaliana and Brassica napus. AtMIR319a activation resulted in a longer silique with thickened and lignified replum, whereas overexpression of an miR319a-resistant version of AtTCP3 (mTCP3) led to a short silique with narrow and less lignified replum. Further genetic and expressional analysis suggested that FUL acted downstream of TCP3 to negatively regulate silique development. Moreover, hyper-activation of BnTCP3.A8, a B. napus homolog of AtTCP3, in rapeseed resulted in an enhanced silique resistance to shattering due to attenuated replum development. Taken together, our findings advance our knowledge of TCP-regulated silique development and provide a potential target for genetic manipulation to reduce silique shattering in Brassica crops. Full article

Loss of seed shattering is a key trait in crop domestication, particularly for grain crops. For wild plants, seed shattering is a crucial mechanism to achieve greater fitness, although in the agricultural context, this mechanism reduces harvesting efficiency, especially under dry conditions. Loss of seed shattering was acquired independently in different monocotyledon and dicotyledon crop species by ‘convergent phenotypic evolution’, leading to similar low dehiscent and indehiscent phenotypes. Here, the main aim is to review the current knowledge about seed shattering in crops, in order to highlight the tissue modifications that underlie the convergent phenotypic evolution of reduced shattering in different types of fruit, from the silique of Brassicaceae species, to the pods of legumes and spikes of cereals. Emphasis is given to legumes, with consideration of recent data obtained for the common bean. The current review also discusses to what extent convergent phenotypes arose from parallel changes at the histological and/or molecular levels. For this reason, an overview is included of the main findings relating to the genetic control of seed shattering in the model species Arabidopsis thaliana and in other important crops. Full article