Chromosomal instability in Lathyrus sativus L

Area of Science:

• Plant genetics
• Cytogenetics
• Molecular biology

Background:

• Lathyrus sativus (grass pea) is an important legume crop.
• The LSD-1 variety of Lathyrus sativus displays unusual characteristics.
• Somatic chromosome number instability can impact plant development and reproduction.

Purpose of the Study:

• To investigate the phenomenon of somatic chromosome number instability in Lathyrus sativus variety LSD-1.
• To determine the extent and patterns of this chromosomal variation.
• To explore potential genetic mechanisms and implications of this instability.

Main Methods:

• Microscopic examination of root tip and shoot tip mitoses.
• Chromosome counting and analysis in dividing cells.
• Assessment of seedling and pollen characteristics.

Main Results:

• Approximately 54% of LSD-1 seedlings displayed intra-individual variation in somatic chromosome number (ranging from 2n=14-3).
• Chromosomal variability was observed in about 60% of dividing cells within affected seedlings.
• Two seedlings were identified as triploid (2n=21), indicating polyploidization events.
• Pollen polymorphism was noted in the LSD-1 strain, potentially linked to chromosomal instability.

Conclusions:

• Genetic factors likely control the somatic chromosome number instability in LSD-1.
• Spindle abnormalities, chromosome degradation, and minute chromosomes are potential contributing mechanisms.
• The observed chromosomal variation is a probable cause of pollen polymorphism in this variety.
• Understanding this phenomenon could have implications for breeding and genetic research in Lathyrus sativus.