The pattern of seed development and maturation in beach pea (Lathyrus maritimus)

Abstract

The developmental patterns of seed, seed coat, and hardseededness were studied in naturally growing crop plants of beach pea (Lathyrus maritimus (L.) Bigel.) at six reproductive growth stages (S1-S6). Grass pea (Lathyrus sativus L.) seeds were used for comparison in some experiments. The accumulation of fresh and dry weight in pod shell and seed of beach pea and pod shell of grass pea followed an almost sigmoidal pattern. However, grass pea seed showed a linear pattern of weight accumulation. During maturation, moisture content of pod shells and seeds decreased because of dehydration. Beach pea seeds were able to germinate precociously at S4. Seeds collected between S1 and S3 failed to germinate because of immaturity, whereas the development of hard seed coats prevented germination in seeds gathered at S5 and S6. An imbibition test revealed that hardseededness completely prevented water absorption of S5 and S6 seeds even after 24 days of soaking. In grass pea, precocious seed germination was observed at S3. However, speed of germination, germination percentage, seedling length and dry weight increased as seeds approached maturity. Lipid and protein accumulation in seeds of both species increased progressively with maturity and showed a positive correlation with seed weight accumulation. In both beach pea and grass pea seeds, S6 was identified as a physiological maturity stage.Résumé : Les auteurs ont étudié les patrons de développement de la graine, des téguments et de l'endurcissement chez la gesse maritime (Lathyrus maritimus (L.) Bigel), une culture poussant naturellement, à six stades de sa reproduction (S1-S6). Les graines de la gesse comestible (Lathryus sativus L.) ont été utilisées pour fin de comparaison dans certaines expériences. L'accumulation du poids frais et du poids sec dans les gousses de la gesse maritime et les gousses de la gesse comestible suivent presque le même patron sigmoïde. Cependant, la graine de la gesse maritime montre un patron linéaire d'accumulation du poids. Au cours de la maturation, la teneur en humidité des gousses et des graines diminue suite à la déshydratation. Les graines de la gesse maritime sont capables de germer de façon précoce au stade S4. Les graines récoltées aux stades S1 à S3 ne peuvent germer parce qu'immatures, alors que l'endurcissement des téguments des graines récoltées aux stades S5 et S6 prévient la germination.. Un test d'imbibition révèle que l'endurcissement empêche complètement l'absorption de l'eau aux stades S5 et S6, même après 24 jours d'immersion. Chez la gesse comestible, on observe une germination précoce des graines au stade S3. Cependant, la vitesse de germination, le pourcentage de germination et la longueur des plantules ainsi que le poids sec augmentent à mesure que la maturité approche. L'accumulation de lipides et de protéines dans les graines des deux espèces augmentent progressivement avec la maturité et montrent une corrélation positive avec l'accumulation de poids par la graine. Chez les graines de la gesse maritime, aussi bien que ch...

When Does Hard Coat Impose Dormancy in Legume Seeds? Lotus and Scorpiurus Case Study

“…In the case of S. muricatus , seeds achieved 70% germination at 60% of the maximum dry weight accumulation (23 DAA), while complete germination was reached at 90% of maximum dry weight (34 DAA). These findings agree with those of Chinnasamy and Bal (2003) for Lathyrus spp. and with those of Revell et al (1999) for yellow serradella (Ornithopus compressus L.).…”

Relationship between seed moisture content and acquisition of impermeability in Nelumbo nucifera (Nelumbonaceae)

“…Numerous studies on seed development have shown that the transition from a permeable to impermeable seed coat coincides with the decline in moisture content during the maturation drying phase of seed development (Jaganathan 2016). Indeed, it has been observed in a few species that the seed coat becomes impermeable only when the moisture content of the seeds falls to a specifi c threshold level (Hyde 1954;Gladstones 1958;Egley 1979;Chinnasamy & Bal 2003;Hay et al 2010;Gama-Arachchige et al 2011;Gresta et al 2011). Th us, the number of seeds with impermeable seed coats produced by plants may vary between sites or within years based on the moisture content reached during maturation drying, which is aff ected by the environmental conditions including temperature and relative humidity.…”

Pulse productivity : physiological constraints /

“…germination hard seededness completely prevents imbibitions (Chinnasamy and Bal, 2003). Seeds may germinate at temperature as low as 2-3° C. Plants are able to withstand frost as cold as -8°C.…”

“…The accumulation of fresh and dry weight in fruit walls and seeds during development indicate that fruit walls follow a sigmoid curve, while seeds follow a linear trend. During maturation, moisture content of fruit walls and seeds decreases due to dehydration (Chinnasamy and Bal, 2003). On dry weight basis of seed, content of starch, protein, lipid and thiamine increases, while soluble sugars, sugars, total amino acids, essential and sulphur amino acids, ash and its alkalinity, magnesium, phosphorus, vitamin C, riboflavin, carotenoids, p-carotene, and chlorophyll also increased.…”

“…Content of dietary fibre, iron, calcium and phytic phosphorus follow variable trend. Protein accumulation in seeds increases progressively with maturity and has a positive correlation with seed weight accumulation (Chinnasamy and Bal, 2003;Lisiewsk et tri., 2003).…”