Redactive analysis: In the 1830 copy of the Book of Mormon there is no chapter break here. It is nevertheless a reasonable place for a new beginning, as the end of our current chapter 7 clearly ends a story. What is interesting is that this verse is intercalated between one large story (the return for the family of Ishmael) and the another (the dream of the tree of life). In between those two large stories we have a single verse. Why?
Nephi's narrative (until later in 2 Nephi) is a combination history/personal journal. It recounts historical information, but really only as a background for the effects of the events on Nephi. The historical background is the skeleton on which Nephi hangs the more important spiritual "flesh" of his account.
Verse 1 is one of those historical structural "bones." The events of Lehi's dream and its subsequent effect on Nephi do not occur immediately after the return with Ishmael's family. In fact, it is probable that quite a bit of time passed. From verse 1 we have the impression of time, and of activity, but not of specific events. Verse 1 is a time marker between larger narrations.
Historical analysis: From a historical perspective, the activities of gathering together seeds indicates the beginning of the task of removing themselves from known civilization. While there is as of yet no indication in 1 Nephi that the Lehite band knew where they were going, it is now clear that they knew that they would be far from the normal realms of civilization, and that they would be in that location for enough time that they would be required to set up agriculture to support themselves. Regardless of what they might find in that new place, the storage of familiar crops was a prudent safeguard. Verse 1 tells us that when the brothers were not fighting against each other, the clan prepared for their eventual journey.