ORIGINAL ARTICLE Molecular characterization of maturity genes of soybean involved in photoperiod-insensitivity and long juvenility A. L. Netawane 1 • V. P. Chimote 1 • M. P. Deshmukh 2 • A. A. Kale 1 Received: 12 May 2020 / Accepted: 5 April 2021 / Published online: 27 April 2021 Ó Indian Society for Plant Physiology 2021 Abstract In soybean, delayed sowing dates or lower lati- tudes causes premature flowering in soybean that reduces the vegetative period and thereby the yield. Molecular analysis of the six soybean genotypes viz., photoperiod- insensitive (EC 390977 and MACS330); photoperiod-sen- sitive (KDS 726 and KDS 753) and long juvenile (DT 21 and AGS 25) was done in the present investigation. Six gene specific Cleaved Amplified Polymorphic Markers (CAPS) were used for identifying dysfunctional e3 and e4 mutant alleles responsible for photoperiod-insensitivity. Restriction digestion of the PCR products was observed only with e3-fs CAPS marker; while in rest five CAPS markers no such digestion was observed indicating for absence of the five non-mutant allelic forms (e3-fs, e3-ns, e4-tsu, e4-oto, e4-kes and e4-kam) in these six soybean genotypes. The long juvenile (LJ) trait was assessed by using tightly linked SSR (Satt197 179 and Satt063 116 ) markers which were highly informative, distinguishing the long juvenile genotypes from rest four genotypes. These SSR markers can be used for MAS for transfer of LJ trait from LJ parents to those lacking this trait. To further analyze the sequence of J gene, five primer sets were designed to cover its entire 2827 bp coding region along with small intervening introns (while excluding a 1493 bp intron). DT21 specific polymorphisms were detected in both nucleotide and amino acid sequences. Five additional variations were shared by either or both photoperiod insensitive genotypes with LJ genotypes. Keywords Maturity loci Á Allelic variants Á Earliness Á Photoperiod insensitivity Á Long juvenility Introduction Soybean (Glycine max L. Merr) cultivars vary widely in their response even within a same geographic region with their maturity duration ranging from less than 75 days to over 150 days. Breeding for widely adaptable, early maturing soybean is a prime objective of soybean breeding for its better adaptation to challenging environment and climate conditions. Early maturing varieties provide a drought escape mechanism under rainfed conditions as well as to escape unusual late rains at maturity which hamper germination in subsequent season. Early maturing soybean varieties are suitable for soybean-chickpea crop- ping system, which is popular among rainfed peninsular India. Flowering represents the transition from the vegetative to the reproductive phase in plants. Various external cues, such as photoperiod and temperature, are known to initiate plant flowering under the appropriate seasonal conditions. Soybean is a short-day plant with a quantitative response to photoperiod (Garner & Allard, 1920). Most of the soybean cultivars have a short-day length requirement for floral induction which is suppressed when under long day length. Late sowing dates and/or low latitudes cause premature flowering induction that reduces the length of the vegeta- tive growth period and restricts the development of leaf area and yield. This photoperiod sensitivity varies among & A. L. Netawane akshaynetawane15@gmail.com 1 State Level Biotechnology Centre, Mahatma Phule Krishi Vidyapeeth, Rahuri, Maharashtra 413722, India 2 Soybean Breeder, Agricultural Research Station, Kasbe Digraj, Sangli, Maharashtra, India 123 Plant Physiol. Rep. (April–June 2021) 26(2):343–356 https://doi.org/10.1007/s40502-021-00589-x