‘兰箭3号’箭筈豌豆荚果发育动态及腹缝线结构研究

摘要

T he common vetch (V icia sativ a) is an important annual legume forage at high altitudes .How-ever ,the phenomenon of pod shattering when it matured would casue serious loss of seeds .With V .sativa cultivar Lanjian NO .3 as the research object ,this study analyzed dynamic changes in pod morphological , moisture content ,surface structure of ventral suture ,anatomical structure of ventral suture cross section during pod development in order to explore the pod shattering mechanism of V .sativ a and provide theoret-ical basis for determining its optimal seed harvesting time in production .The results showed that :(1) When the pod of Lanjian NO .3 turned to light brown at about 25-30 days after peak anthesis ,it had com-pleted physiological maturity and its size and dry weight had reached the highest with the moisture content had reduced to the lowest .A crack appeared in the pod ventral suture at 25 days after peak anthesis and it separated completely at 35 days after peak anthesis .(2) The abscission layer cells began to disintegrate at 20 days after peak anthesis .At 25 days after peak anthesis ,all the parenchyma cells of endocarp ,meso-carp and exocarp began to lose water and shrink wherein the portion of endocarp parenchyma cells began to break .The abscission layer cells and the following parenchyma cells disintegrated completely .The inside cell walls of external valve margin cells broke but the outside cell walls which abnormal thickened still re-mained intact and connected two fruit valves which made the pod do not crack .During the period from 25 to 30 days after peak anthesis ,the parenchyma cells of endocarp ,mesocarp and exocarp lost water com-pletely and their cell walls shrank together .At the same time the outside cell walls of external valve mar-gin cells broke into two parts and the two fruit valves of the pod cracked .The research shows that the op-timal harvest time of Lanjian NO .3 seeds was the period from 25 to 30 days after peak anthesis when the pod turned to light brown .The abscission layer cells and machine tensile which generated by cell water loss were the main causes of V .sativa pod crack .Conjecture that the thickening and fused cell walls of ex-ternal valve margin cells were the key structure resistant to pod shattering probably .%箭筈豌豆（V icia sativ a）是高海拔地区重要的一年生豆科牧草，但荚果成熟时的开裂现象会造成种子的严重损失。该研究以栽培品种‘兰箭3号’为对象，对其荚果在发育过程中的形态特征、水分含量、腹缝线表面结构及腹缝线横截面解剖结构的动态变化进行观察分析，以探讨箭筈豌豆荚果的裂荚机理，为生产中确定种子收获的适宜时间提供理论依据。结果显示：（1）‘兰箭3号’约在盛花后25～30 d荚果变为浅棕色，此时荚果已完成生理成熟，且荚果的大小和干重均达到最大值，含水量降到最小值；盛花后25 d荚果腹缝线出现裂缝，盛花后35 d腹缝线完全裂开。（2）‘兰箭3号’于盛花后20 d腹缝线处离层细胞开始解体；盛花后25 d ，内、中、外果皮的薄壁细胞均开始失水皱缩，其中内果皮的薄壁细胞部分已开始破裂，离层细胞及其下面的薄壁细胞完全解体，外部果瓣缘细胞内侧细胞壁破裂，但外侧异常加厚的细胞壁仍然保持完整并连接两个果瓣，使荚果不开裂；盛花后30～35 d ，内、中、外果皮的薄壁细胞完全失水，细胞壁皱缩在一起，同时外部果瓣缘细胞外侧细胞壁断裂成两部分，荚果的两个果瓣裂开。研究表明，盛花后25～30 d荚果失去绿色变为浅棕色时是‘兰箭3号’的适宜收获时间，且离层和细胞失水产生的机械拉力是导致箭筈豌豆荚果开裂的主要原因，推测外部果瓣缘细胞外侧增厚融合的细胞壁很可能是‘兰箭3号’抵抗裂荚的关键结构。