Characterization of Drupe Traits in Sixty-Six Teak Candidate Plus Trees (CPTs) in Gujarat Forests of India for Enhanced Seed Collection and Fruit Production

The most valuable timber of the world i.e., teak was recognized as king of wood due to its wood quality such as durability, physical and aesthetic wood property for multiple uses. It is distributed throughout India and Southeast Asia and known for center of teak genetic diversity. It has a high demand in international market and national market due to multifarious uses. However, the natural population of Teak is decreasing in India due to anthropogenic activities, deforestation, climate change and other environmental factors. In addition, the poor seed yield per tree and extremely low seed germination rates are significant problems for the teak plantation industry and production of quality seed. Nevertheless, there are huge gap between demand and supply of industrial timber in India. This can be fulfilled by the teak plantation within agroforestry systems and degraded forest lands. Gujarat forest has natural teak populations which falls in the conjunction point of Western Ghats of India. Hence, sixty-six CPTs of teak were screened out for quality seed collection and reproduction from natural teak populations. Fruits of teak were collected from various CPTs with wide range of geographic locations in Gujarat forests of India. The drupe and stone morphometric traits were studied to capture the phenotypic and genotypic variations; to select better traits on the basis of repeatability coefficient; and to look geographic location effect on various fruit characters and inter-character correlations for quality seed collection and fruit production. Present result showed significant differences (p≤ 0.0001) in all the studied fruit traits among 66 CPTs of Tectona grandis. Drupe were lengthiest in GJNBD 0467 (12.36 mm), broadest in the GJNBD 0467 (14.75 mm) and heaviest in the GJAH 1056 (0.73 g) CPT, whereas smallest in GJNBD 1122 (8.3 mm), narrowest in GJNBD 1122 (9.91 mm) and lightest in GJNBD 1122 (0.32 g) CPT. Stone were longest in GJNBD 0467 (8.71 mm), thickest in GJAH 1056 (10.01 mm) and heaviest in GJAH 1056 (0.51 g) CPT, while shortest in GJNBD 1122 (6.06 mm), thinnest stone in GJNBD 1122 (7.56 mm) and lightest in GJNBD 0772 (0.22 g) CPT. Overall, GJNBD 0467, GJAH 1056, GJNBD 0950, GJAH 0844 and GJNBD 0470 CPTs were superior for studied traits as compared to others. CPT repeatability coefficient was higher for drupe characters as compared to stone parameters, where selection can be made for drupe length for future tree improvement programme. The genetic improvement via CPT selection is better option for maintaining genetic diversity of Teak, its conservation and management. Latitude showed strong negative correlation with drupe length, stone length and drupe mass. Longitude was negatively correlated with stone length and width. Thus, the geographical parameter has an impact on the seed formation, evolution and plant fitness. The strong correlations were found among seed morphometric characters which influenced to seed development and creating fitness interaction with continuous changing environment.