Effects of microscopic testa color and morphologyon the water uptake ability and drought tolerance of germination-stage rapeseed (Brassica napus L.)

Abstract

Drought is one of the most important abiotic stressors that affect crop yield. Therefore, the aim of the present study was to investigate correlations between germination-stage drought tolerance and the microscopic testa (i.e., seed coat) characteristics (color and papilla morphology) and imbibition abilities of 35 rapeseed ( Brassica napus L.) accessions. After 2 h imbibition, seed water uptake (fresh weight increase) was significantly positively correlated with testa hue ( H HSB ), brightness ( B HSB ,), blue ( B RGB ), and lightness ( L *), with correlation coefficients of 0.38, 0.34, 0.53, and 0.36, respectively, and significantly negatively correlated with saturation ( S HSB ), greenness-redness ( a *), blueness-yellowness ( b *), magenta ( M ), and yellow components ( Y ), with correlation coefficients of −0.53, −0.40, −0.53, −0.39, and −0.55, respectively. Furthermore, 5-h seed water uptake was significantly positively correlated with number of papillae (No.P), mean papillae area (APA), the papillae area ratio (PAR), gray value of red channel of papillae, with correlation coefficients of 33, 0.36, 0.43, and 0.43, respectively. Under drought conditions, genotypes with more rapid water absorption exhibited higher germination rates and stronger drought tolerance, and the germination rate and drought tolerance of black-seeded accessions were highest, followed by red-seeded accessions and then yellow-seeded accessions, which exhibited the lowest germination rate and drought tolerance. Germination rate was significantly negatively correlated with B RGB , H HSB , L*, D g , and D b and significantly positively correlated with S HSB and Y , regardless of drought conditions. At the germination stage, D b TP was negatively correlated with drought tolerance.

Imbibition and Germination of Seeds with Economic and Ecological Interest: Physical and Biochemical Factors Involved

“…In accordance with Moncaleano-Escandon [21], the deterioration process begins with the loss of selective permeability of the cellular membranes and ends with the loss of the germination capacity. Water is distributed in crevices, cracks, and flaws in the seed cover, and is absorbed by the seed tissues [44]. Water-uptake measurements, taken during this phase have shown these rates to be: (1) temperature-dependent; and (2) accompanied by increases in respiration rate and in light sensitivity in some seed species [21,25,45,46].…”

Genome‐wide association studies for rice seed germination under drought stress using 3VmrMLM

“…In direct‐seeding rice, rapid seed germination and vigorous seedling growth are essential for achieving high crop yield (He, Yang, et al., 2019). Drought stress is particularly detrimental to seed germination, leading to delayed seedling establishment in dry direct‐seeded rice (He et al., 2021; Zheng et al., 2016). Therefore, studying the natural variation and genetic mechanisms underlying drought tolerance during germination can contribute to the genetic improvement of rice growth and grain yield.…”

Identification and Characterization of the BnFAR1/FHY3 Gene Family and Expression Analysis under Shading and Low-Temperature Responses in Brassica napus L.

“…B. napus is not only valuable as a vegetable and an edible oil [23], but can also be used for ornamental purposes, as a source of nectar, in the remediation of heavy metal pollution and as an industrial raw material crop [24,25]. Moreover, B. napus cake contains higher protein, making it suitable for use as high-quality feed, with a positive impact on promoting and developing the breeding industry [24][25][26][27]. Zhao et al (2019) found that B. napus rotation can increase the nutrient content of the soil and improve the biological characteristics of the soil, thereby increasing the yield of subsequent crops and contributing to the green and sustainable development of agriculture [28].…”