Influence of seed coat compactness around cotyledons, protein andmineral composition on mechanical strength of soybean[Glycine max (L.) Merrill] seed coat

Abstract

The critical problem of soybean seed is susceptibility to mechanical processes due to structural limitations of seed and seed coat. The X-radiography of soybean seed revealed the orientation of seed coat around the cotyledons and cultivars like JS 335, JS 9752, JS 71-05, JS 95-60, MACS 124, Pusa 40, Punjab 1 and Type 49 had very compact seed coat around cotyledons. In NRC 12, NRC 37, RKS 18 and SL 525 where the gap between seed coat and cotyledons was significantly very high and non uniform making seed coat very much vulnerable to cracking. Seed coat minerals- calcium, silicon, zinc, iron and lignin content were found to vary significantly among cultivars. Significant genotypic variability for strength of seed coat was observed among the soybean cultivars. A very close relationship was found between strength of seed coat and seed coat compactness. Highly significant correlation was found between mechanical strength and seed coat lignin, iron and zinc content. Quantitative and qualitative variation for seed coat protein among soybean cultivars was revealed and higher protein content was found linked with mechanically strong seed coat. The result revealed that selection for these seed coat parameters in varietal improvement programme may be very fruitful for development of varieties having resistance to field weathering and mechanical damage.

Seed coat composition in black and white soybean seeds with differential water permeability

“…These results indicate that the impermeable black seed coat of Bhatt contains comparatively more protein than the permeable white seed coat of JS 335. Similar differences were found by Kuchlan et al (2018) and Mullin & Xu (2001) in seed coats of soybean Seed coats of Bhatt contained more phenols (6.76 AE 0.47 mgÁg À1 ) than those of JS 335 (0.71 AE 0.53 mgÁg À1 ). The relationship between phenol content and permeability is well established (Marbach & Mayer 1974).…”

“…Similar differences were found by Kuchlan et al . (2018) and Mullin & Xu (2001) in seed coats of soybean genotypes. However, further studies are needed to establish the impact of protein content on seed coat permeability.…”

Transcriptional Profile of Soybean Seeds with Contrasting Seed Coat Color

“…Several studies have shown that HCT silencing through RNAi and knockout results in lower lignin content and reduces growth in the plant Arabidopsis [ 64 , 65 , 66 , 67 , 68 ]. Higher levels of lignin in the seed are associated with higher physiological quality, reduced damage from moisture, less damage caused by storage fungi, and less mechanical damage [ 19 , 69 , 70 ]. Additionally, soybean varieties with black seed coats have better storability due to having smaller pores in their membranes and higher lignin contents [ 20 ].…”

“…Regarding seed quality, it has already been observed that genotypes with high levels of lignin in their seed coats present greater thickness and, consequently, greater tissue resistance to possible physical damage due to moisture, mechanical damage, and/or the presence of pathogens [ 14 , 15 , 16 , 17 , 18 , 19 ]. Lignin is also associated with more thickness in other tissues.…”

Insights into mechanisms of seed longevity in soybean: a review

“…Hilum is another prime seed part that delivers nutrients and photosynthates to the developing embryo and when damaged leads to seed infections and inferior seed quality. Likewise, properties of seed coat surface like cutin deposition, cuticle cracks, gap between seed coat and cotyledon and depositions influence water permeability, fungal invasion, and ultimately seed longevity in soybean (Ranathunge et al, 2010;Kuchlan et al, 2018).…”