Table 1.
Information of rice varieties released in different ages since 1930s in China.
Fig 1.
The schematic of bending moment (BM) was calculated using the following formula, BM = SL (stem length)×FW (fresh weight).
Then, lodging index (bending moment/breaking resistance×100) was calculated for N3 internode according to Amano et al. (1993) [23]. The diameter of N3 near the lower node was measured after removing the leaf sheath. The dry weight of N3 with leaf sheath was measured after oven drying at 80°C to constant weight. Dry weight of N3 with leaf sheath per unit internode length (g cm−1) was also calculated [14, 24].
Fig 2.
Changes in SL (A, B), NL (C, D), ND (EF, f), FW (G, H) and NDW (I, J) with the year of release of the varieties grown in 2013 and 2014. SL: stem length from the base of N3 internode to the tip of the panicle, NL: N3 internode length, ND: N3 internode diameter, FW: stem fresh weight, NDW: N3 internode dry weight.
Table 2.
Stem length (SL), N3 internode length (NL), N3 internode diameter (ND), Stem fresh weight (FW) and N3 internode dry weight (DW) of rice varieties grown in 2013 and 2014 released in different ages since 1930s in China.
Fig 3.
Changes in DWUL (A, B), BM (C, D), BR (E, F) and LI (G, H) with the year of release of the rice varieties grown in 2013 and 2014. DWUL: N3 internode dry weight per unit length, BM: bending moment, BR: breaking resistance, LI: lodging index.
Table 3.
Dry weight per unit length of N3 internode (DWUL), Bending Moment (BR), Breaking Resistance (BR), Lodging Index (LI) and Visual Score of Lodging (VSL) of rice varieties grown in 2013 and 2014 released in different ages since 1930s in China.
Table 4.
Correlation coefficient (r) among lodging-related traits of rice varieties grown in 2013 and 2014 in different ages since 1930s in China.
Fig 4.
The correlation between grain yield and SL (A, B), NL (C, D), ND (E, F), FW (G, H) and NDW (I, J) of the rice varieties grown in 2013 and 2014. SL: stem length from the base of N3 internode to the tip of the panicle, NL: N3 internode length, ND: N3 internode diameter, FW: stem fresh weight, NDW: N3 internode dry weight.
Fig 5.
The correlation between grain yield and DWUL (A, B), BM (C, D), BR (E, F) and LI (G, H) of the rice varieties grown in 2013 and 2014. DWUL: N3 internode dry weight per unit length, BM: bending moment, BR: breaking resistance, LI: lodging index.